Anti-Orai1 antibody

ABSTRACT

It is intended to provide a therapeutic and/or prophylactic agent for transplant rejections, immunological diseases, allergic diseases, inflammatory diseases, thrombosis, cancers, etc., targeting human Orai1. The present invention provides, for example, a pharmaceutical composition comprising an antibody that specifically recognizes human Orai1 and has the activity of inhibiting human T cell activation.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the National Stage of International Application No.PCT/JP2015/072305, filed Aug. 6, 2015, which claims priority to JapanesePatent Application No. 2014-161449, filed Aug. 7, 2014, each of which isincorporated herein by reference in its entirety.

TECHNICAL FIELD

The present invention relates to the provision of a more highly activeanti-Orai1 antibody for the treatment of disorders and diseases.

STATEMENT REGARDING SEQUENCE LISTING

The sequence listing associated with this application is provided intext format in lieu of a paper copy and is hereby incorporated byreference into the specification.

BACKGROUND ART

Calcium release activated calcium (CRAC) channels are a subset ofstore-operated channels (SOC) which are opened in response to thedepletion of calcium stored in the intracellular endoplasmic reticulum,and are responsible for the entry of extracellular calcium to particularnon-excitable cells, particularly, cells of the immune system includingT cells and mast cells, and the resulting activation of the cells.Inhibitors of CRAC channel activity are known in the art, and theiridentification and therapeutic potentials are described by Feske et al.(Non Patent Literature 1 and 2).

Orai1 (CRACM1: calcium release activated calcium modulator 1,transmembrane protein 142A: TMEM142A), a 4-pass transmembrane proteincomposed of 301 amino acid residues, has been identified as a componentconstituting the pore forming subunit of CRAC channels by forming ahomotetramer (Patent Literature 1 and Non Patent Literature 3 to 5). TheOrai gene family comprises the human Orai1 gene together with the humanOrai2 and human Orai3 genes which each have 90% or higher homology tothe human Orai1 gene (Non Patent Literature 6). In some cases, thepossibility of forming a heterotetramer or a heterohexamer containingthe Orai2 and/or Orai3 protein and Orai1 has also been reported (NonPatent Literature 7 and 8). Orai1 is constituted by N terminal and Cterminal cytoplasmic regions which couple to STIM-1 (stromal interactionmolecule 1) or STIM-2, which is a protein sensing the depletion ofcalcium stored in the intracellular endoplasmic reticulum, and 4transmembrane domains, the first extracellular loop domain beingcomposed of approximately 20 amino acid residues, and the secondextracellular loop domain being composed of approximately 40 amino acidresidues (Non Patent Literature 9). The DNA sequence and the amino acidsequence of Orai1 are available on a public database and can be referredto under, for example, Accession Nos. NM_032790 and NP_116179 (NCBI).

It has been found that a congenital defect in the function of the humanOrai1 gene eliminates CRAC channel activity and cancels responses of thebody to immunogens, resulting in severe immunodeficient conditions.Therefore, the molecular function of Orai1 has been proved essential forthe activation of CRAC channels (Non Patent Literature 10 and 11). Thus,function blocking antibodies targeting the Orai1 molecule can serve asinhibitors of CRAC channel activity.

In the light of information suggesting that inhibitors of CRAC channelactivity may be used for treating patients with immunological diseases,allergic diseases, inflammatory diseases, transplantation rejection ofcells or organs, thrombosis, cancers, etc. (Non Patent Literature 12),attempts have been made to obtain anti-Orai1 antibodies with the aim ofinhibiting the molecular function of Orai1, and their effects have beenstudied (Patent Literature 2 and 3 and Non Patent Literature 13 and 14).Although this literature indicates that each antibody alone inhibits theactivation of T cells, the inhibitory activity is not yet sufficientlystrong. The clinical application of these antibodies as biologicstargeting Orai1 may not satisfy medical needs in terms of the need forhigh doses or frequent administration, limited administration methods,or the like.

CITATION LIST Patent Literature

-   Patent Literature 1: International Publication No. WO07/081804-   Patent Literature 2: International Publication No. WO11/063277-   Patent Literature 3: International Publication No. WO13/091903

Non Patent Literature

-   Non Patent Literature 1: Feske S, Nature Rev. Immunol. 7, p. 690-702    (2007)-   Non Patent Literature 2: Derler I, et al., Expert Opin. Drug    Discovery 3 (7), p. 787-800 (2008)-   Non Patent Literature 3: Prakriya M, et al., Nature 443, p. 230-233    (2006)-   Non Patent Literature 4: Vig M, et al., Science 312, p. 1220-1223    (2006)-   Non Patent Literature 5: Park C Y, et al., Cell 136, p. 876-890    (2008)-   Non Patent Literature 6: Mercer J C, et al., J. Biol. Chem. 281, p.    24979-24990 (2006)-   Non Patent Literature 7: Gwack Y, et al., J. Biol. Chem. 282, p.    16232-16243 (2007)-   Non Patent Literature 8: Hou X, et al., Science 338, p. 1308-1313    (2012)-   Non Patent Literature 9: Vig M, et al., Curr. Biol. 16, p. 2073-2079    (2006)-   Non Patent Literature 10: Feske S, Nature 441, p. 179-185 (2006)-   Non Patent Literature 11: McCarl C A, et al., J. Allergy Clin.    Immunol. 124, p. 1311-1318 (2009)-   Non Patent Literature 12: McCarl C A, et al., J. Immunol. 185, p.    5845-5858 (2010)-   Non Patent Literature 13: Lin F, et al., J. Pharmacol. Exp. Ther.    345, p. 225-238 (2013)-   Non Patent Literature 14: Cox J H, et al., PLOS ONE 8 (12), e82944    (2013)

SUMMARY OF INVENTION Technical Problem

An object of the present invention is to provide a therapeutic and/orprophylactic agent for transplant rejections, immunological diseases,allergic diseases, inflammatory diseases, thrombosis, cancers, etc.

Solution to Problem

The present inventors have obtained rat anti-Orai1 antibodies for thepurpose of searching for substances having a therapeutic and/orprophylactic effect on transplant rejections, immunological diseases,allergic diseases, inflammatory diseases, thrombosis, or cancers. Theobtained rat anti-Orai1 antibodies have been humanized, and the CDRs,frameworks, and variable regions of the humanized antibodies have beenengineered. In this way, the present invention has been completed.

Specifically, the present invention encompasses the following aspects:

(1) An antibody or an antigen binding fragment of the antibody whichspecifically binds to the amino acid sequence represented by SEQ ID NO:2, wherein the heavy chain sequence comprises a variable region havingCDRH1, CDRH2, and CDRH3, wherein the CDRH1 consists of the amino acidsequence represented by SEQ ID NO: 102, the CDRH2 consists of an aminoacid sequence represented by any one of SEQ ID NOs: 104, 106, 107, and108, and the CDRH3 consists of an amino acid sequence represented by SEQID NO: 109 or 110; andthe light chain sequence comprises a variable region having CDRL1,CDRL2, and CDRL3, wherein the CDRL1 consists of an amino acid sequencerepresented by any one of SEQ ID NOs: 93, 94, and 95, the CDRL2 consistsof an amino acid sequence represented by any one of SEQ ID NOs: 96, 97,and 98, and the CDRL3 consists of the amino acid sequence represented bySEQ ID NO: 101.(2) The antibody or the antigen binding fragment of the antibodyaccording to (1), wherein the heavy chain sequence comprises a variableregion having CDRH1, CDRH2, and CDRH3, wherein the CDRH1 consists of theamino acid sequence represented by SEQ ID NO: 102, the CDRH2 consists ofthe amino acid sequence represented by SEQ ID NO: 106, and the CDRH3consists of the amino acid sequence represented by SEQ ID NO: 110; andthe light chain sequence comprises a variable region having CDRL1,CDRL2, and CDRL3, wherein the CDRL1 consists of the amino acid sequencerepresented by SEQ ID NO: 93, the CDRL2 consists of the amino acidsequence represented by SEQ ID NO: 96, and the CDRL3 consists of theamino acid sequence represented by SEQ ID NO: 101.(3) The antibody or the antigen binding fragment of the antibodyaccording to (1), wherein the heavy chain sequence comprises a variableregion having CDRH1, CDRH2, and CDRH3, wherein the CDRH1 consists of theamino acid sequence represented by SEQ ID NO: 102, the CDRH2 consists ofthe amino acid sequence represented by SEQ ID NO: 106, and the CDRH3consists of the amino acid sequence represented by SEQ ID NO: 110; andthe light chain sequence comprises a variable region having CDRL1,CDRL2, and CDRL3, wherein the CDRL1 consists of the amino acid sequencerepresented by SEQ ID NO: 94, the CDRL2 consists of the amino acidsequence represented by SEQ ID NO: 97, and the CDRL3 consists of theamino acid sequence represented by SEQ ID NO: 101.(4) The antibody or the antigen binding fragment of the antibodyaccording to (1), wherein the heavy chain sequence comprises a variableregion having CDRH1, CDRH2, and CDRH3, wherein the CDRH1 consists of theamino acid sequence represented by SEQ ID NO: 102, the CDRH2 consists ofthe amino acid sequence represented by SEQ ID NO: 106, and the CDRH3consists of the amino acid sequence represented by SEQ ID NO: 110; andthe light chain sequence comprises a variable region having CDRL1,CDRL2, and CDRL3, wherein the CDRL1 consists of the amino acid sequencerepresented by SEQ ID NO: 95, the CDRL2 consists of the amino acidsequence represented by SEQ ID NO: 98, and the CDRL3 consists of theamino acid sequence represented by SEQ ID NO: 101.(5) The antibody or the antigen binding fragment of the antibodyaccording to (1), wherein the heavy chain sequence comprises a variableregion having CDRH1, CDRH2, and CDRH3, wherein the CDRH1 consists of theamino acid sequence represented by SEQ ID NO: 102, the CDRH2 consists ofthe amino acid sequence represented by SEQ ID NO: 107, and the CDRH3consists of the amino acid sequence represented by SEQ ID NO: 110; andthe light chain sequence comprises a variable region having CDRL1,CDRL2, and CDRL3, wherein the CDRL1 consists of the amino acid sequencerepresented by SEQ ID NO: 93, the CDRL2 consists of the amino acidsequence represented by SEQ ID NO: 96, and the CDRL3 consists of theamino acid sequence represented by SEQ ID NO: 101.(6) The antibody or the antigen binding fragment of the antibodyaccording to (1), wherein the heavy chain sequence comprises a variableregion having CDRH1, CDRH2, and CDRH3, wherein the CDRH1 consists of theamino acid sequence represented by SEQ ID NO: 102, the CDRH2 consists ofthe amino acid sequence represented by SEQ ID NO: 108, and the CDRH3consists of the amino acid sequence represented by SEQ ID NO: 110; andthe light chain sequence comprises a variable region having CDRL1,CDRL2, and CDRL3, wherein the CDRL1 consists of the amino acid sequencerepresented by SEQ ID NO: 93, the CDRL2 consists of the amino acidsequence represented by SEQ ID NO: 96, and the CDRL3 consists of theamino acid sequence represented by SEQ ID NO: 101.(7) The antibody or the antigen binding fragment of the antibodyaccording to (1), wherein the heavy chain sequence comprises a variableregion having CDRH1, CDRH2, and CDRH3, wherein the CDRH1 consists of theamino acid sequence represented by SEQ ID NO: 102, the CDRH2 consists ofthe amino acid sequence represented by SEQ ID NO: 104, and the CDRH3consists of the amino acid sequence represented by SEQ ID NO: 109; andthe light chain sequence comprises a variable region having CDRL1,CDRL2, and CDRL3, wherein the CDRL1 consists of the amino acid sequencerepresented by SEQ ID NO: 93, the CDRL2 consists of the amino acidsequence represented by SEQ ID NO: 96, and the CDRL3 consists of theamino acid sequence represented by SEQ ID NO: 101.(8) The antibody or the antigen binding fragment of the antibodyaccording to (1) or (2), wherein the antibody comprises a heavy chainvariable region sequence consisting of amino acid residues frompositions 20 to 136 in the amino acid sequence represented by SEQ ID NO:62 and a light chain variable region sequence consisting of amino acidresidues from positions 21 to 126 in the amino acid sequence representedby SEQ ID NO: 56.(9) The antibody or the antigen binding fragment of the antibodyaccording to (8), wherein the antibody consists of a heavy chainsequence consisting of amino acid residues from positions 20 to 465 or20 to 466 in the amino acid sequence represented by SEQ ID NO: 62 and alight chain sequence consisting of amino acid residues from positions 21to 234 in the amino acid sequence represented by SEQ ID NO: 56.(10) The antibody or the antigen binding fragment of the antibodyaccording to (8), wherein the antibody consists of a heavy chainsequence consisting of amino acid residues from positions 20 to 465 or20 to 466 in the amino acid sequence represented by SEQ ID NO: 70 and alight chain sequence consisting of amino acid residues from positions 21to 234 in the amino acid sequence represented by SEQ ID NO: 56.(11) The antibody or the antigen binding fragment of the antibodyaccording to (1) or (3), wherein the antibody comprises a heavy chainvariable region sequence consisting of amino acid residues frompositions 20 to 136 in the amino acid sequence represented by SEQ ID NO:62 and a light chain variable region sequence consisting of amino acidresidues from positions 21 to 126 in the amino acid sequence representedby SEQ ID NO: 58.(12) The antibody or the antigen binding fragment of the antibodyaccording to (11), wherein the antibody consists of a heavy chainsequence consisting of amino acid residues from positions 20 to 465 or20 to 466 in the amino acid sequence represented by SEQ ID NO: 62 and alight chain sequence consisting of amino acid residues from positions 21to 234 in the amino acid sequence represented by SEQ ID NO: 58.(13) The antibody or the antigen binding fragment of the antibodyaccording to (1) or (4), wherein the antibody comprises a heavy chainvariable region sequence consisting of amino acid residues frompositions 20 to 136 in the amino acid sequence represented by SEQ ID NO:62 and a light chain variable region sequence consisting of amino acidresidues from positions 21 to 126 in the amino acid sequence representedby SEQ ID NO: 60.(14) The antibody or the antigen binding fragment of the antibodyaccording to (13), wherein the antibody consists of a heavy chainsequence consisting of amino acid residues from positions 20 to 465 or20 to 466 in the amino acid sequence represented by SEQ ID NO: 62 and alight chain sequence consisting of amino acid residues from positions 21to 234 in the amino acid sequence represented by SEQ ID NO: 60.(15) The antibody or the antigen binding fragment of the antibodyaccording to (1) or (5), wherein the antibody comprises a heavy chainvariable region sequence consisting of amino acid residues frompositions 20 to 136 in the amino acid sequence represented by SEQ ID NO:64 and a light chain variable region sequence consisting of amino acidresidues from positions 21 to 126 in the amino acid sequence representedby SEQ ID NO: 56.(16) The antibody or the antigen binding fragment of the antibodyaccording to (15), wherein the antibody consists of a heavy chainsequence consisting of amino acid residues from positions 20 to 465 or20 to 466 in the amino acid sequence represented by SEQ ID NO: 64 and alight chain sequence consisting of amino acid residues from positions 21to 234 in the amino acid sequence represented by SEQ ID NO: 56.(17) The antibody or the antigen binding fragment of the antibodyaccording to (1) or (6), wherein the antibody comprises a heavy chainvariable region sequence consisting of amino acid residues frompositions 20 to 136 in the amino acid sequence represented by SEQ ID NO:66 and a light chain variable region sequence consisting of amino acidresidues from positions 21 to 126 in the amino acid sequence representedby SEQ ID NO: 56.(18) The antibody or the antigen binding fragment of the antibodyaccording to (17), wherein the antibody consists of a heavy chainsequence consisting of amino acid residues from positions 20 to 465 or20 to 466 in the amino acid sequence represented by SEQ ID NO: 66 and alight chain sequence consisting of amino acid residues from positions 21to 234 in the amino acid sequence represented by SEQ ID NO: 56.(19) The antibody or the antigen binding fragment of the antibodyaccording to (1) or (7), wherein the antibody comprises a heavy chainvariable region sequence consisting of amino acid residues frompositions 20 to 136 in the amino acid sequence represented by SEQ ID NO:43 and a light chain variable region sequence consisting of amino acidresidues from positions 21 to 126 in the amino acid sequence representedby SEQ ID NO: 56.(20) The antibody or the antigen binding fragment of the antibodyaccording to (19), wherein the antibody consists of a heavy chainsequence consisting of amino acid residues from positions 20 to 465 or20 to 466 in the amino acid sequence represented by SEQ ID NO: 43 and alight chain sequence consisting of amino acid residues from positions 21to 235 in the amino acid sequence represented by SEQ ID NO: 56.(21) The antigen binding fragment of the antibody according to any oneof (1) to (20), wherein the antigen binding fragment is selected fromthe group consisting of Fab, F(ab′)2, Fab′, and Fv.(22) The antibody according to any one of (1) to (8), (11), (13), (15),(17), and (19), wherein the antibody is an scFv.(23) A pharmaceutical composition comprising at least any one antibodyor antigen binding fragment of the antibody according to (1) to (22).(24) The pharmaceutical composition according to (23), wherein thepharmaceutical composition is a therapeutic and/or prophylactic agentfor transplant rejections, immune-related diseases, allergic diseases,inflammatory diseases, or cancers, an antiplatelet or antithromboticactivator, or an inhibitor of Orai1-expressing-cell activation.(25) The pharmaceutical composition according to (24), wherein thetransplant rejections are rejection responses and host versus graftreactions to the transplantation of an organ or a tissue such as theheart, the kidney, the liver, the bone marrow, or the skin, and graftversus host disease caused by the transplantation of hematopoietic cells(bone marrow, peripheral blood, umbilical cord blood, etc.).(26) The pharmaceutical composition according to (24), wherein theimmune-related diseases are connective tissue or musculoskeletaldiseases (rheumatoid arthritis, ankylosing spondylitis, systemic lupuserythematosus, scleroderma, polymyositis, dermatomyositis, etc.),hematological diseases (aplastic anemia, idiopathic thrombocytopenicpurpura, etc.), gastrointestinal diseases (Crohn disease, ulcerativecolitis, etc.), neurological diseases (multiple sclerosis, myastheniagravis, etc.), ophthalmic diseases (uveitis, etc.), vascular diseases(Behcet's disease, Wegener's granulomatosis, etc.), epidermal diseases(psoriasis, pemphigus, leukoderma, etc.), endocrine diseases (type 1diabetes mellitus, autoimmune thyroiditis, Graves' disease, Hashimoto'sdisease, etc.), and the like, the allergic diseases are atopicdermatitis, asthma, anaphylaxis, anaphylactoid reaction, food allergy,rhinitis, otitis media, drug reaction, insect bite reaction, reaction toplants, latex allergy, conjunctivitis, urticaria, and the like, and theinflammatory diseases are inflammatory renal diseases(glomerulonephritis, nephrosis, etc.), inflammatory pulmonary diseases(chronic obstructive pulmonary disease, cystic fibrosis, interstitialpneumonia, etc.), inflammatory bowel diseases (ulcerative colitis,ileitis, etc.), inflammatory hepatic diseases (autoimmune hepatitis,viral hepatitis, etc.), inflammatory cardiac diseases (myocarditis,ischemic heart disease, atherosclerosis, etc.), inflammatory skindiseases (contact dermatitis, eczema, etc.), inflammatory eye diseases(trachoma, endophthalmitis, etc.), inflammatory central nervous diseases(meningitis, encephalomyelitis, autoimmune encephalitis, etc.),inflammatory joint diseases (arthritis, osteoarthritis, etc.), systemicinflammations (sepsis, bleeding, hypersensitivity, shock symptomsattributed to cancer chemotherapy or the like, etc.), and the like.(27) The pharmaceutical composition according to (24), wherein thecancers are breast cancer, lung cancer, skin cancer, leukemia, and thelike, and cases in which the antiplatelet or antithrombotic activity isuseful for treatment and/or prevention are myocardial infarction,stroke, ischemic heart diseases, thrombosis, and the like, and cases inwhich the inhibition of Orai1 expressing cell activation is useful fortreatment and/or prevention are mast cell leukemia, mastocytosis,basophilic leukemia, endometriosis, tubular aggregate myopathy,Stormorken syndrome, rheumatoid arthritis, ankylosing spondylitis,atopic dermatitis, and the like.(28) A polynucleotide encoding an antibody or an antigen bindingfragment of the antibody according to any one of (1) to (22).(29) A vector comprising a polynucleotide according to (28).(30) A transformed host cell comprising a polynucleotide according to(28).(31) A transformed host cell comprising a vector according to (29).(32) A method for producing an antibody or an antigen binding fragmentof the antibody according to any one of (1) to (22), comprising the stepof culturing a host cell according to (30) or (31) and purifying anantibody from the culture product.(33) An antibody or an antigen binding fragment of the antibody whichspecifically binds to the amino acid sequence represented by SEQ ID NO:2, wherein the concentration at which the amount of IL-2 released fromJurkat cells treated with PMA and A23187 is inhibited by 50% is 80 ng/mLor lower.(34) The antibody or the antigen binding fragment of the antibodyaccording to (33), wherein the concentration at which the amount of IL-2released from Jurkat cells treated with PMA and A23187 is inhibited by50% is 10 ng/mL or lower.(35) An antibody or an antigen binding fragment of the antibody whichspecifically binds to the amino acid sequence represented by SEQ ID NO:2, wherein the concentration at which the amount of IL-2 released fromhuman peripheral blood mononuclear cells (PBMC) treated with PMA andA23187 is inhibited by 50% is 100 ng/mL or lower.(36) The antibody or the antigen binding fragment of the antibodyaccording to (35), wherein the concentration at which the amount of IL-2released from human PBMC treated with PMA and A23187 is inhibited by 50%is 20 ng/mL or lower.(37) An antibody or an antigen binding fragment of the antibody whichspecifically binds to the amino acid sequence represented by SEQ ID NO:2, wherein the concentration at which the amount of IFN-7 released fromhuman PBMC treated with PMA and A23187 is inhibited by 50% is 800 ng/mLor lower.(38) The antibody or the antigen binding fragment of the antibodyaccording to (37), wherein the concentration at which the amount ofIFN-7 released from human PBMC treated with PMA and A23187 is inhibitedby 50% is 40 ng/mL or lower.

Advantageous Effects of Invention

According to the present invention, a therapeutic and/or prophylacticagent for transplant rejections, immunological diseases, allergicdiseases, inflammatory diseases, thrombosis, or cancers based on theinhibition of CRAC channel activity as the mechanism of action can beobtained.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram showing that R118 and R198 each bind topcDNA3.1-hOrai1 transfected HEK293T cells in a concentration dependentmanner.

FIG. 2 is a diagram showing that R118 and R198 each inhibit, in aconcentration dependent manner, the release of IL-2 from Jurkat cellstreated with PMA and A23187.

FIG. 3 is a diagram showing that cR118 and cR198 each bind topcDNA3.1-hOrai1 transfected HEK293T cells in a concentration dependentmanner.

FIG. 4 is a diagram showing that cR118 and cR198 each inhibit, in aconcentration dependent manner, the release of IL-2 from Jurkat cellstreated with PMA and A23187.

FIG. 5 is a diagram showing that humanized anti-human Orai1 antibodieshR198_H1/L1, hR198_H2/L2, hR198_H3/L3, and hR198_H4/L4 each bind topcDNA3.1-hOrai1 transfected HEK293T cells in a concentration dependentmanner, as with the parent antibody cR118 or cR198.

FIG. 6 is a diagram showing that the humanized anti-human Orai1antibodies each inhibit, in a concentration dependent manner, therelease of IL-2 from Jurkat cells treated with PMA and A23187.

FIGS. 7A-7C are diagrams showing that mutated Fab clones LCDR60, LCDR67,and LCDR83 (FIG. 7A), CE151 and PE057 (FIG. 7B), and HCDR046, HCDR047,HEP087, HEP124, and HEP237 (FIG. 7C) obtained by ribosome display eachstrongly bind to pcDNA3.1-hOrai1 transfected HEK293T cells as comparedwith the parent antibody Fab hR198_H4/L4-Fab.

FIG. 8 is a diagram showing that affinity maturation antibodieshR198_H3/LG1, hR198_HG1/LG1, hR198_HG1/LG2, hR198_HG1/LG3,hR198_HG2/LG1, and hR198_HG3/LG1 each bind to pcDNA3.1-hOrai1transfected HEK293T cells at a level equivalent to or stronger than thatof the parent antibody hR198_H3/L3 or hR198_H4/L4.

FIG. 9 is a diagram showing that the affinity maturation antibodies eachinhibit, in a concentration dependent manner, the release of IL-2 fromJurkat cells treated with PMA and A23187.

FIG. 10 is a diagram showing that 10F8, 14F74, and 17F6 antibodies eachbind to pcDNA3.1-hOrai1 transfected HEK293T cells.

FIG. 11 is a diagram showing that hR198_HG1/LG1, hR198_HG1-LALA/LG1,2C1.1, and 5H3.1 antibodies each bind to pcDNA3.1-hOrai1 transfectedHEK293T cells.

FIG. 12 is a diagram showing that the anti-Orai1 monoclonal antibodieseach inhibit, in a concentration dependent manner, the release of IL-2from Jurkat cells treated with PMA and A23187.

FIG. 13 is a diagram showing the half maximal inhibitory concentrations(IC₅₀) and the 80% inhibitory concentrations (IC₈₀) of hR198_HG1/LG1,hR198_HG1-LALA/LG1, 2C1.1, 5H3.1, 10F8, 14F74, and 17F6 against IL-2release from Jurkat cells.

FIG. 14 is a diagram showing a nucleotide sequence encoding a R118 lightchain variable region and an amino acid sequence of the variable region.

FIG. 15 is a diagram showing a nucleotide sequence encoding a R118 heavychain variable region and an amino acid sequence of the variable region.

FIG. 16 is a diagram showing a nucleotide sequence encoding a R198 lightchain variable region and an amino acid sequence of the variable region.

FIG. 17 is a diagram showing a nucleotide sequence encoding a R198 heavychain variable region and an amino acid sequence of the variable region.

FIG. 18 is a diagram showing a nucleotide sequence encoding a humanchimerized cR118 light chain and an amino acid sequence of the lightchain.

FIG. 19 is a diagram showing a nucleotide sequence encoding a humanchimerized cR198 light chain and an amino acid sequence of the lightchain.

FIG. 20 is a diagram showing a nucleotide sequence encoding a humanchimerized cR118 heavy chain and an amino acid sequence of the heavychain.

FIG. 21 is a diagram showing a nucleotide sequence encoding a humanchimerized cR198 heavy chain and an amino acid sequence of the heavychain.

FIG. 22 is a diagram showing a nucleotide sequence encoding a hR198_L1type light chain and an amino acid sequence of the light chain.

FIG. 23 is a diagram showing a nucleotide sequence encoding a hR198_L2type light chain and an amino acid sequence of the light chain.

FIG. 24 is a diagram showing a nucleotide sequence encoding a hR198_L3type light chain and an amino acid sequence of the light chain.

FIG. 25 is a diagram showing a nucleotide sequence encoding a hR198_L4type light chain and an amino acid sequence of the light chain.

FIG. 26 is a diagram showing a nucleotide sequence encoding a hR198_H1type heavy chain and an amino acid sequence of the heavy chain.

FIG. 27 is a diagram showing a nucleotide sequence encoding a hR198_H2type heavy chain and an amino acid sequence of the heavy chain.

FIG. 28 is a diagram showing a nucleotide sequence encoding a hR198_H3type heavy chain and an amino acid sequence of the heavy chain.

FIG. 29 is a diagram showing a nucleotide sequence encoding a hR198_H4type heavy chain and an amino acid sequence of the heavy chain.

FIG. 30 is a diagram showing a nucleotide sequence encoding a hR198_LG1type light chain and an amino acid sequence of the light chain.

FIG. 31 is a diagram showing a nucleotide sequence encoding a hR198_LG2type light chain and an amino acid sequence of the light chain.

FIG. 32 is a diagram showing a nucleotide sequence encoding a hR198_LG3type light chain and an amino acid sequence of the light chain.

FIG. 33 is a diagram showing a nucleotide sequence encoding a hR198_HG1type heavy chain and an amino acid sequence of the heavy chain.

FIG. 34 is a diagram showing a nucleotide sequence encoding a hR198_HG2type heavy chain and an amino acid sequence of the heavy chain.

FIG. 35 is a diagram showing a nucleotide sequence encoding a hR198_HG3type heavy chain and an amino acid sequence of the heavy chain.

FIG. 36 is a diagram showing a nucleotide sequence encoding ahR198_H4-LALA type heavy chain and an amino acid sequence of the heavychain.

FIG. 37 is a diagram showing a nucleotide sequence encoding ahR198_HG1-LALA type heavy chain and an amino acid sequence of the heavychain.

FIG. 38 is a diagram showing SEQ ID NOs corresponding to CDR sequencescontained in each of cR118, cR198, hR198_L1 to hR198_L4, and hR198_LG1to hR198_LG3 light chains and each of cR118, cR198, hR198_H1 tohR198_H4, hR198_HG1 to hR198_HG3, hR198_H4-LALA, and hR198_HG1-LALAheavy chains.

FIG. 39 is a diagram showing a nucleotide sequence encoding a 2C1.1antibody heavy chain and an amino acid sequence of the heavy chain.

FIG. 40 is a diagram showing a nucleotide sequence encoding a 2C1.1antibody light chain and an amino acid sequence of the light chain.

FIG. 41 is a diagram showing a nucleotide sequence encoding a 5H3.1antibody heavy chain and an amino acid sequence of the heavy chain.

FIG. 42 is a diagram showing a nucleotide sequence encoding a 5H3.1antibody light chain and an amino acid sequence of the light chain.

FIG. 43 is a diagram showing a nucleotide sequence encoding a 10F8antibody heavy chain and an amino acid sequence of the heavy chain.

FIG. 44 is a diagram showing a nucleotide sequence encoding a 10F8antibody light chain and an amino acid sequence of the light chain.

FIG. 45 is a diagram showing a nucleotide sequence encoding a 14F74antibody heavy chain and an amino acid sequence of the heavy chain.

FIG. 46 is a diagram showing a nucleotide sequence encoding a 14F74antibody light chain and an amino acid sequence of the light chain.

FIG. 47 is a diagram showing a nucleotide sequence encoding a 17F6antibody heavy chain and an amino acid sequence of the heavy chain.

FIG. 48 is a diagram showing a nucleotide sequence encoding a 17F6antibody light chain and an amino acid sequence of the light chain.

FIG. 49 is a diagram showing a nucleotide sequence encoding a hR198_H0type heavy chain and an amino acid sequence of the heavy chain.

FIG. 50 is a diagram showing a nucleotide sequence encoding a hR198_H5type heavy chain and an amino acid sequence of the heavy chain.

FIG. 51 is a diagram showing that the anti-Orai1 monoclonal antibodieseach inhibit, in a concentration dependent manner, the release of IL-2from human PBMC treated with PMA and A23187.

FIG. 52 is a diagram showing the half maximal inhibitory concentrations(IC₅₀) and the 80% inhibitory concentrations (IC₈₀) of hR198_HG1/LG1,hR198_HG1-LALA/LG1, 2C1.1, 5H3.1, 10F8, 14F74, and 17F6 against IL-2release from human PBMC.

FIG. 53 is a diagram showing that the anti-Orai1 monoclonal antibodieseach inhibit, in a concentration dependent manner, the release of IFN-7from human PBMC treated with PMA and A23187.

FIG. 54 is a diagram showing the half maximal inhibitory concentrations(IC₅₀) and the 80% inhibitory concentrations (IC₈₀) of hR198_HG1/LG1,hR198_HG1-LALA/LG1, 2C1.1, 5H3.1, 10F8, 14F74, and 17F6 against IFN-γrelease from human PBMC.

FIG. 55 is a diagram showing that hR198_HG1/LG1 inhibits weight lossassociated with graft versus host disease that develops by thetransplantation of human PBMC to severe combined immunodeficient mice.

FIG. 56 is a diagram showing that hR198_HG1/LG1 suppresses passivecutaneous anaphylaxis reaction induced in human Orai1 knock-in mice.

FIGS. 57A-57C are diagrams showing that hR198_HG1/LG1 suppressed delayedtype hypersensitivity reaction induced in human Orai1 knock-in mice, ateach point in time of 6 hours (FIG. 57A), 24 hours (FIG. 57B), and 48hours (FIG. 57C) after antigen administration.

FIG. 58 is a diagram showing viscosity measured at concentrations of 90mg/mL, 120 mg/mL, and 150 mg/mL of the hR198_HG1/LG1, hR198_H3/LG1,hR198_HG1-LALA/LG1, and 2C1.1 antibodies.

DESCRIPTION OF EMBODIMENTS

In the present specification, the term “gene” includes not only DNA butmRNA, cDNA, and cRNA.

In the present specification, the term “polynucleotide” is used with thesame meaning as a nucleic acid and also includes DNA, RNA, probes,oligonucleotides, and primers.

In the present specification, the term “polypeptide” and the term“protein” are used interchangeably with each other.

In the present specification, the term “RNA fraction” refers to afraction containing RNA.

In the present specification, the term “cell” includes cells withinindividual animal and cultured cells.

In the present specification, the term “Orai1” is used with the samemeaning as Orai1 protein.

In the present specification, the term “antigen binding fragment of theantibody” means a partial fragment of the antibody having bindingactivity against the antigen and includes Fab, F(ab′)2, Fv, scFv,diabodies, linear antibodies, and multispecific antibodies formed fromantibody fragments, etc. The antigen binding fragment of the antibodyalso includes Fab′, which is a monovalent fragment of antibody variableregions obtained by the treatment of F(ab′)2 under reducing conditions.However, the antigen binding fragment of the antibody is not limited tothese molecules as long as the antigen binding fragment has the abilityto bind to the antigen. Such an antigen binding fragment includes notonly a fragment obtained by treating a full length molecule of theantibody protein with an appropriate enzyme but also a protein producedin appropriate host cells using a genetically engineered antibody gene.

The heavy and light chains of an antibody molecule are known to eachhave three complementarity determining regions (CDRs). Thecomplementarity determining regions are also called hypervariabledomains. These regions are located in the variable regions of theantibody heavy and light chains. These sites have a particularly highlyvariable primary structure and are separated at three positions on therespective primary structures of heavy and light chain polypeptidechains. In the present specification, the complementarity determiningregions of the antibody are referred to as CDRH1, CDRH2, and CDRH3 fromthe amino terminus of the heavy chain amino acid sequence for thecomplementarity determining regions of the heavy chain and as CDRL1,CDRL2, and CDRL3 from the amino terminus of the light chain amino acidsequence for the complementarity determining regions of the light chain.These sites are proximal to each other on the three-dimensionalstructure and determine specificity for the antigen to be bound.

In the present invention, the phrase “hybridizing under stringentconditions” means hybridization under conditions involving hybridizationat 68° C. in a commercially available hybridization solution ExpressHybHybridization Solution (Clontech Laboratories, Inc.), or hybridizationat 68° C. in the presence of 0.7 to 1.0 M NaCl using a DNA immobilizedfilter, followed by washing at 68° C. using an SSC solution having a 0.1to 2× concentration (SSC having a 1× concentration consists of 150 mMNaCl and 15 mM sodium citrate) which permits identification, orhybridization under conditions equivalent thereto.

In the present invention, the term “host versus graft reaction” refersto the hyperimmune state of a recipient observed after organtransplantation, and damage to the transplanted organ resultingtherefrom.

In the present invention, the term “graft versus host disease” refers tosymptoms manifested by the immunological attack of a recipient bytransplanted cells after hematopoietic cell transplantation.

1. Orai1

Orai1 used in the present invention can be directly purified from Tcells or mast cells of a human, a nonhuman mammal (e.g., a guinea pig, arat, a mouse, a rabbit, a pig, a sheep, cattle, or a monkey), or achicken, or can be used in a cell membrane fraction prepared from thecells. Alternatively, Orai1 can be synthesized in vitro or obtained byproduction from host cells by gene manipulation. In such genemanipulation, specifically, Orai1 cDNA is inserted into a vector thatpermits expression, and then Orai1 can be synthesized in a solutioncontaining an enzyme, a substrate, and an energy substance necessary fortranscription and translation, or expressed by transformation of hostcells of a different prokaryote or eukaryote to obtain the protein.

The nucleotide sequence of human Orai1 cDNA is registered underAccession No: NM_032790 in GenBank. The nucleotide sequence of mouseOrai1 cDNA is registered under Accession No: NM_175423 in GenBank. Thenucleotide sequence encoding human Orai1 is shown in SEQ ID NO: 1 of theSequence Listing, and the amino acid sequence of human Orai1 is shown inSEQ ID NO: 2 of the Sequence Listing. Orai1 is also called calciumrelease activated calcium modulator 1 (CRACM1) or transmembrane protein142A (TMEM142A), all of which indicate the same molecule.

The Orai1 cDNA can be obtained by a so-called PCR method which involvescarrying out polymerase chain reaction (hereinafter, referred to as“PCR”) (Saiki, R. K., et al., Science, (1988) 239, 487-49), for example,with a cDNA library of organs expressing Orai1 mRNA as a template usingprimers specifically amplifying the Orai1 cDNA.

The term “Orai1 cDNA” also includes a polynucleotide that hybridizesunder stringent conditions to a polynucleotide consisting of anucleotide sequence complementary to the nucleotide sequence encodinghuman or mouse Orai1 and that encodes a protein having biologicalactivity equivalent to Orai1. The term “Orai1 cDNA” further includes acDNA for a splicing variant that has been transcribed from the human ormouse Orai1 gene locus or a polynucleotide that hybridizes understringent conditions to a polynucleotide consisting of a nucleotidesequence complementary to the splicing variant, and that encodes aprotein having biological activity equivalent to Orai1.

The term “Orai1” also includes a protein that consists of an amino acidsequence derived from the amino acid sequence of human or mouse Orai1 oran amino acid sequence thereof free from the signal sequence by thesubstitution, deletion, or addition of 1, 2 or 3, or 4 or 5 amino acids,and has biological activity equivalent to Orai1. The term “Orai1”further comprises a protein that consists of an amino acid sequenceencoded by a splicing variant transcribed from the human or mouse Orai1gene locus, or an amino acid sequence derived from this amino acidsequence by the substitution, deletion, or addition of 1, 2 or 3, or 4or 5 amino acids, and has biological activity equivalent to Orai1.

2. Production of Anti-Orai1 Antibody

The antibody against Orai1 of the present invention can be obtainedaccording to routine methods by immunizing an animal with Orai1 or anarbitrary polypeptide selected from the amino acid sequence of Orai1 andcollecting and purifying the antibody produced in vivo. The species forOrai1 used as an antigen is not limited to a human, and the animal maybe immunized with Orai1 derived from a nonhuman animal such as a mouseor a rat. In this case, the obtained antibody binding to theheterologous Orai1 can be tested for its cross-reactivity with humanOrai1 to select an antibody applicable to human diseases. The antigenOrai1 can be obtained by allowing host cells to produce the Orai1 geneby gene manipulation. Specifically, a vector that permits expression ofthe Orai1 gene is prepared and transferred to host cells to express thegene. The expressed Orai1 can be purified.

The antibody against Orai1 of the present invention can also be obtainedby use of a DNA immunization method. The DNA immunization method is anapproach which involves transfecting an animal (e.g., mouse or rat) withan antigen expression plasmid and expressing the antigen in the animalto induce immunity against the antigen. The transfection approachincludes a method of directly injecting the plasmid into muscle, amethod of injecting a complex of the plasmid and a liposome,polyethylenimine, or the like into a vein, an approach using a viralvector, an approach of injecting gold particles attached to the plasmidusing a gene gun, a hydrodynamic method of rapidly injecting a plasmidsolution in a large amount into a vein, and the like. A technique calledin vivo electroporation, which involves applying electroporation to asite given the intramuscularly injected plasmid, is known as an approachfor improving the expression level of the transfection method ofinjecting the expression plasmid into muscle (Aihara H, Miyazaki J., NatBiotechnol. 1998 September; 16 (9): 867-70 or Mir L M, Bureau M F, GehlJ, Rangara R, Rouy D, Caillaud J M, Delaere P, Branellec D, Schwartz B,Scherman D., Proc Natl Acad Sci USA. 1999 Apr. 13; 96 (8): 4262-7). Thisapproach further improves the expression level by treating the musclewith hyaluronidase before the intramuscular injection of the plasmid(McMahon JM1, Signori E, Wells K E, Fazio V M, Wells D J., Gene Ther.2001 August; 8 (16): 1264-70).

A monoclonal antibody can also be obtained according to methods known inthe art (e.g., Kohler and Milstein, Nature (1975) 256, p. 495-497; andKennet, R. ed., Monoclonal Antibodies, p. 365-367, Plenum Press, N.Y.(1980)) by fusing antibody-producing cells that produce the antibodyagainst Orai1 with myeloma cells to establish hybridomas. Specificexamples of such a method are described in International PublicationNos. WO09/48072 (published on Apr. 16, 2009) and WO10/117011 (publishedon Oct. 14, 2010).

Actual examples of the rat anti-human Orai1 antibody thus establishedcan include R118 and R198 antibodies. The amino acid sequence of thelight chain variable region of the R118 antibody is shown in SEQ ID NO:11 of the Sequence Listing, and the sequence of the heavy chain variableregion of the R118 antibody is shown in SEQ ID NO: 13 of the SequenceListing. The amino acid sequence of the light chain variable region ofthe R198 antibody is shown in SEQ ID NO: 15 of the Sequence Listing, andthe sequence of the heavy chain variable region of the R198 antibody isshown in SEQ ID NO: 17 of the Sequence Listing.

The antibody of the present invention includes the monoclonal antibodyagainst Orai1 described above as well as a recombinant antibodyartificially engineered for the purpose of, for example, reducingheterogeneous antigenicity against humans, for example, a chimericantibody and a humanized antibody, a human antibody, and the like. Theseantibodies can be produced by use of known methods.

Examples of the chimeric antibody can include a chimeric antibodycomprising variable regions and constant regions of antibodies derivedfrom different species, for example, the variable regions of a mouse- orrat-derived antibody joined to human-derived constant regions (see Proc.Natl. Acad. Sci. U.S.A., 81, 6851-6855, (1984)).

Examples of the chimeric antibody derived from the rat anti-human Orai1antibody R118 can include an antibody consisting of a light chaincomprising a light chain variable region consisting of amino acidresidues at positions 21 to 126 of SEQ ID NO: 23 and a heavy chaincomprising a heavy chain variable region consisting of amino acidresidues at positions 20 to 136 of SEQ ID NO: 27. One example of such aR118-derived chimeric antibody can include an antibody consisting of alight chain consisting of amino acid residues at positions 21 to 234 ofSEQ ID NO: 23 and a heavy chain consisting of amino acid residues atpositions 20 to 466 of SEQ ID NO: 27. In the present specification, thisantibody is referred to as “cR118” or a “cR118 antibody”.

Examples of the chimeric antibody derived from the rat anti-human Orai1antibody R198 can include an antibody consisting of a light chaincomprising a light chain variable region consisting of amino acidresidues at positions 21 to 126 of SEQ ID NO: 25 and a heavy chaincomprising a heavy chain variable region consisting of amino acidresidues at positions 20 to 136 of SEQ ID NO: 29. One example of such aR198-derived chimeric antibody can include an antibody consisting of alight chain consisting of amino acid residues at positions 21 to 234 ofSEQ ID NO: 25 and a heavy chain consisting of amino acid residues atpositions 20 to 466 of SEQ ID NO: 29. In the present specification, thisantibody is referred to as “cR198” or a “cR198 antibody”.

The sequence of the chimeric antibody against Orai1 described above canbe artificially engineered to prepare a humanized antibody as a generecombinant antibody, for the purpose of, for example, reducingheterogeneous antigenicity against humans. The antibody of the presentinvention includes an antibody whose CDRs are engineered CDRs of ahumanized antibody. These antibodies can be produced by use of knownmethods.

Examples of the humanized antibody can include an antibody comprisingcomplementarity determining regions (CDRs) alone grafted into ahuman-derived antibody (see Nature (1986) 321, p. 522-525), and anantibody comprising the CDR sequences as well as amino acid residues ofa portion of the framework grafted into a human antibody (InternationalPublication No. WO90/07861).

The humanized antibody derived from the cR118 or cR198 antibody retainsall of the 6 CDR sequences derived from cR118 or cR198 and has theactivity of inhibiting the activation of T cells. The light chainvariable region of the humanized antibody retains any one of a CDRL1consisting of the amino acid sequence represented by SEQ ID NO: 92(RASQSIGNSLS) and a CDRL1 consisting of the amino acid sequencerepresented by SEQ ID NO: 116 (RASQSISNSLS), a CDRL2 consisting of theamino acid sequence represented by SEQ ID NO: 96 (STSTLES), and any oneof a CDRL3 consisting of the amino acid sequence represented by SEQ IDNO: 99 (LQFATFPDT) and a CDRL3 shown in SEQ ID NO: 100 (LQFATYPDT).Also, the heavy chain variable region of the humanized antibody retainsany one of a CDRH1 consisting of the amino acid sequence represented bySEQ ID NO: 102 (AYYIS) and a CDRH1 shown in SEQ ID NO: 103 (SYYIS), anyone of a CDRH2 consisting of the amino acid sequence represented by SEQID NO: 104 (YIDMGNGRTNYNARFKG) and a CDRH2 shown in SEQ ID NO: 105(YVDMGNGRTNYNEKFKG), and a CDRH3 consisting of the amino acid sequencerepresented by SEQ ID NO: 109 (DSNWGVDY). These amino acid sequences ofthe CDRs are also shown in FIG. 38.

Examples of the antibody having a preferred combination of the CDRs caninclude an antibody comprising CDRL1 consisting of the amino acidsequence represented by SEQ ID NO: 92, CDRL2 consisting of the aminoacid sequence represented by SEQ ID NO: 96, CDRL3 consisting of theamino acid sequence represented by SEQ ID NO: 100, CDRH1 consisting ofthe amino acid sequence represented by SEQ ID NO: 103, CDRH2 consistingof the amino acid sequence represented by SEQ ID NO: 105, and CDRH3consisting of the amino acid sequence represented by SEQ ID NO: 109, andan antibody comprising CDRL1 consisting of the amino acid sequencerepresented by SEQ ID NO: 92, CDRL2 consisting of the amino acidsequence represented by SEQ ID NO: 96, CDRL3 consisting of the aminoacid sequence represented by SEQ ID NO: 99, CDRH1 consisting of theamino acid sequence represented by SEQ ID NO: 102, CDRH2 consisting ofthe amino acid sequence represented by SEQ ID NO: 104, and CDRH3consisting of the amino acid sequence represented by SEQ ID NO: 109.

Preferred examples of the humanized antibody can include an antibodyconsisting of a light chain comprising a light chain variable regionconsisting of amino acid residues at positions 21 to 126 of SEQ ID NO:31 and a heavy chain comprising a heavy chain variable region consistingof amino acid residues at positions 20 to 136 of SEQ ID NO: 39, anantibody consisting of a light chain comprising a light chain variableregion consisting of amino acid residues at positions 21 to 126 of SEQID NO: 33 and a heavy chain comprising a heavy chain variable regionconsisting of amino acid residues at positions 20 to 136 of SEQ ID NO:41, an antibody consisting of a light chain comprising a light chainvariable region consisting of amino acid residues at positions 21 to 126of SEQ ID NO: 35 and a heavy chain comprising a heavy chain variableregion consisting of amino acid residues at positions 20 to 136 of SEQID NO: 43, and an antibody consisting of a light chain comprising alight chain variable region consisting of amino acid residues atpositions 21 to 126 of SEQ ID NO: 37 and a heavy chain comprising aheavy chain variable region consisting of amino acid residues atpositions 20 to 136 of SEQ ID NO: 45.

More preferred examples thereof can include an antibody consisting of alight chain consisting of amino acid residues at positions 21 to 234 ofSEQ ID NO: 31 and a heavy chain consisting of amino acid residues atpositions 20 to 466 of SEQ ID NO: 39, an antibody consisting of a lightchain consisting of amino acid residues at positions 21 to 234 of SEQ IDNO: 33 and a heavy chain consisting of amino acid residues at positions20 to 466 of SEQ ID NO: 41, an antibody consisting of a light chainconsisting of amino acid residues at positions 21 to 234 of SEQ ID NO:35 and a heavy chain consisting of amino acid residues at positions 20to 466 of SEQ ID NO: 43, and an antibody consisting of a light chainconsisting of amino acid residues at positions 21 to 234 of SEQ ID NO:37 and a heavy chain consisting of amino acid residues at positions 20to 466 of SEQ ID NO: 45.

The antibody of the present invention may be an antibody with enhancedability to bind to Orai1 obtained by further mutating the humanizedantibody described above. Such an approach is called affinitymaturation. Specific examples of the method can include a ribosomedisplay method. The ribosome display method is a method which involvesusing a tripartite complex of a protein bound to an mRNA having thegenetic information thereof via a ribosome and isolating a gene sequenceencoding the protein that binds to a target molecule (Stafford R L. etal., Protein Eng. Des. Sel. 2014 (4): 97-109).

The light chain variable region of the antibody genetically engineeredby the method described above retains any one of a CDRL1 consisting ofthe amino acid sequence represented by SEQ ID NO: 93 (RASQSIGGSLS), aCDRL1 consisting of the amino acid sequence represented by SEQ ID NO: 94(HASQNIGGSLS), and a CDRL1 consisting of the amino acid sequencerepresented by SEQ ID NO: 95 (HASRNIGGSLS), any one of a CDRL2consisting of the amino acid sequence represented by SEQ ID NO: 96(STSTLES), a CDRL2 consisting of the amino acid sequence represented bySEQ ID NO: 97 (LTSTLDW), and a CDRL2 consisting of the amino acidsequence represented by SEQ ID NO: 98 (LTSSLDW), and a CDRL3 consistingof the amino acid sequence represented by SEQ ID NO: 101 (LQFAIFPDS).Also, the heavy chain variable region of the genetically engineeredantibody retains a CDRH1 consisting of the amino acid sequencerepresented by SEQ ID NO: 102 (AYYIS), any one of a CDRH2 consisting ofthe amino acid sequence represented by SEQ ID NO: 104(YIDMGNGRTNYNARFKG), a CDRH2 consisting of the amino acid sequencerepresented by SEQ ID NO: 106 (YIDMGNGRTDYNARFKG), a CDRH2 consisting ofthe amino acid sequence represented by SEQ ID NO: 107(YIDMGNGRTDYNGRFKG), and a CDRH2 shown in SEQ ID NO: 108(YIDMGNGRTDYNMRFKG), and a CDRH3 consisting of the amino acid sequencerepresented by SEQ ID NO: 109 (DSNWGVDY) or a CDRH3 consisting of theamino acid sequence represented by SEQ ID NO: 110 (DSNWGADY). Theseamino acid sequences of the CDRs are also shown in FIG. 38.

Examples of the antibody having a preferred combination of the CDRs caninclude an antibody comprising a CDRL1 consisting of the amino acidsequence represented by SEQ ID NO: 93, a CDRL2 consisting of the aminoacid sequence represented by SEQ ID NO: 96, a CDRL3 consisting of theamino acid sequence represented by SEQ ID NO: 101, a CDRH1 consisting ofthe amino acid sequence represented by SEQ ID NO: 102, a CDRH2consisting of the amino acid sequence represented by SEQ ID NO: 106, anda CDRH3 consisting of the amino acid sequence represented by SEQ ID NO:110, an antibody comprising a CDRL1 consisting of the amino acidsequence represented by SEQ ID NO: 94, a CDRL2 consisting of the aminoacid sequence represented by SEQ ID NO: 97, a CDRL3 consisting of theamino acid sequence represented by SEQ ID NO: 101, a CDRH1 consisting ofthe amino acid sequence represented by SEQ ID NO: 102, a CDRH2consisting of the amino acid sequence represented by SEQ ID NO: 106, anda CDRH3 consisting of the amino acid sequence represented by SEQ ID NO:110, an antibody comprising a CDRL1 consisting of the amino acidsequence represented by SEQ ID NO: 95, a CDRL2 consisting of the aminoacid sequence represented by SEQ ID NO: 98, a CDRL3 consisting of theamino acid sequence represented by SEQ ID NO: 101, a CDRH1 consisting ofthe amino acid sequence represented by SEQ ID NO: 102, a CDRH2consisting of the amino acid sequence represented by SEQ ID NO: 106, anda CDRH3 consisting of the amino acid sequence represented by SEQ ID NO:110, an antibody comprising a CDRL1 consisting of the amino acidsequence represented by SEQ ID NO: 93, a CDRL2 consisting of the aminoacid sequence represented by SEQ ID NO: 96, a CDRL3 consisting of theamino acid sequence represented by SEQ ID NO: 101, a CDRH1 consisting ofthe amino acid sequence represented by SEQ ID NO: 102, a CDRH2consisting of the amino acid sequence represented by SEQ ID NO: 107, anda CDRH3 consisting of the amino acid sequence represented by SEQ ID NO:110, an antibody comprising a CDRL1 consisting of the amino acidsequence represented by SEQ ID NO: 93, a CDRL2 consisting of the aminoacid sequence represented by SEQ ID NO: 96, a CDRL3 consisting of theamino acid sequence represented by SEQ ID NO: 101, a CDRH1 consisting ofthe amino acid sequence represented by SEQ ID NO: 102, a CDRH2consisting of the amino acid sequence represented by SEQ ID NO: 108, anda CDRH3 consisting of the amino acid sequence represented by SEQ ID NO:110, and an antibody comprising a CDRL1 consisting of the amino acidsequence represented by SEQ ID NO: 93, a CDRL2 consisting of the aminoacid sequence represented by SEQ ID NO: 96, a CDRL3 consisting of theamino acid sequence represented by SEQ ID NO: 101, a CDRH1 consisting ofthe amino acid sequence represented by SEQ ID NO: 102, a CDRH2consisting of the amino acid sequence represented by SEQ ID NO: 104, anda CDRH3 consisting of the amino acid sequence represented by SEQ ID NO:109.

Preferred examples of the genetically-engineered-CDR antibody caninclude an antibody consisting of a light chain comprising a light chainvariable region consisting of amino acid residues at positions 21 to 126of SEQ ID NO: 56 and a heavy chain comprising a heavy chain variableregion consisting of amino acid residues at positions 20 to 136 of SEQID NO: 62, an antibody consisting of a light chain comprising a lightchain variable region consisting of amino acid residues at positions 21to 126 of SEQ ID NO: 58 and a heavy chain comprising a heavy chainvariable region consisting of amino acid residues at positions 20 to 136of SEQ ID NO: 62, an antibody consisting of a light chain comprising alight chain variable region consisting of amino acid residues atpositions 21 to 126 of SEQ ID NO: 60 and a heavy chain comprising aheavy chain variable region consisting of amino acid residues atpositions 20 to 136 of SEQ ID NO: 62, an antibody consisting of a lightchain comprising a light chain variable region consisting of amino acidresidues at positions 21 to 126 of SEQ ID NO: 56 and a heavy chaincomprising a heavy chain variable region consisting of amino acidresidues at positions 20 to 136 of SEQ ID NO: 64, an antibody consistingof a light chain comprising a light chain variable region consisting ofamino acid residues at positions 21 to 126 of SEQ ID NO: 56 and a heavychain comprising a heavy chain variable region consisting of amino acidresidues at positions 20 to 136 of SEQ ID NO: 66, and an antibodyconsisting of a light chain comprising a light chain variable regionconsisting of amino acid residues at positions 21 to 126 of SEQ ID NO:56 and a heavy chain comprising a heavy chain variable region consistingof amino acid residues at positions 20 to 136 of SEQ ID NO: 43.

Preferred examples of the antibody comprising the light chain variableregion and the heavy chain variable region described above can includean antibody consisting of a light chain consisting of amino acidresidues at positions 21 to 234 of SEQ ID NO: 56 and a heavy chainconsisting of amino acid residues at positions 20 to 466 of SEQ ID NO:62, an antibody consisting of a light chain consisting of amino acidresidues at positions 21 to 234 of SEQ ID NO: 58 and a heavy chainconsisting of amino acid residues at positions 20 to 466 of SEQ ID NO:62, an antibody consisting of a light chain consisting of amino acidresidues at positions 21 to 234 of SEQ ID NO: 60 and a heavy chainconsisting of amino acid residues at positions 20 to 466 of SEQ ID NO:62, an antibody consisting of a light chain consisting of amino acidresidues at positions 21 to 234 of SEQ ID NO: 56 and a heavy chainconsisting of amino acid residues at positions 20 to 466 of SEQ ID NO:64, an antibody consisting of a light chain consisting of amino acidresidues at positions 21 to 234 of SEQ ID NO: 56 and a heavy chainconsisting of amino acid residues at positions 20 to 466 of SEQ ID NO:66, and an antibody consisting of a light chain consisting of amino acidresidues at positions 21 to 234 of SEQ ID NO: 56 and a heavy chainconsisting of amino acid residues at positions 20 to 466 of SEQ ID NO:43.

For circumventing cytotoxicity against normal cells expressing humanOrai1, it is desirable that an antibody should have low effectoractivity. The effector activity is known to differ among antibodysubclasses. The following characteristics are observed, for example,IgG4 has low ADCC and CDC activities, and IgG2 has CDC activity, but haslow ADCC activity. On the basis of these features, it is possible toprepare an antibody with reduced ADCC and CDC activities by replacingthe constant regions of IgG1 with the constant regions of IgG2 or IgG4.Also, it is possible to prepare an IgG1 antibody with reduced ADCC andCDC activities by partially substituting the constant region sequencesof IgG1 with reference to IgG2 or IgG4. As one example, Marjan Hezarehet al., Journal of Virology, 75 (24): 12161-12168 (2001) shows that theADCC and CDC activities of IgG1 are reduced by replacing each of theleucine residues at positions 234 and 235 (the positions are indicatedby the EU index of Kabat et al.) of IgG1 with an alanine residue.

Examples of the heavy chain of the anti-Orai1 antibody prepared by themethod described above can include a heavy chain sequence shown in SEQID NO: 68 or 70. The heavy chain shown in SEQ ID NO: 68 or 70 can becombined with each light chain sequence described in the presentspecification and used as a therapeutic antibody. Specific examples ofthe light chain to be combined can include the light chain described inSEQ ID NO: 31, 33, 35, 37, 56, 58, or 60. Examples of the antibodyhaving a preferred combination of the light chain and the heavy chaincan include an antibody consisting of a light chain consisting of aminoacid residues at positions 21 to 234 of SEQ ID NO: 56 and a heavy chainconsisting of amino acid residues at positions 20 to 466 of SEQ ID NO:70, an antibody consisting of a light chain consisting of amino acidresidues at positions 21 to 234 of SEQ ID NO: 58 and a heavy chainconsisting of amino acid residues at positions 20 to 466 of SEQ ID NO:70, and an antibody consisting of a light chain consisting of amino acidresidues at positions 21 to 234 of SEQ ID NO: 60 and a heavy chainconsisting of amino acid residues at positions 20 to 466 of SEQ ID NO:70.

It is known that carboxyl terminal lysine residues are deleted in theheavy chains of antibodies produced in cultured mammalian cells (Journalof Chromatography A, 705: 129-134 (1995)). It is also known that twocarboxyl terminal amino acid residues (glycine and lysine) are deletedin heavy chains, and a proline residue newly positioned at the carboxylterminus is amidated (Analytical Biochemistry, 360: 75-83 (2007)).However, such deletion and modification of heavy chain sequences has noinfluence on the ability of the antibody to bind to the antigen and theeffector functions (complement activation and antibody dependentcellular cytotoxic effect, etc.) of the antibody. Thus, the antibody ofthe present invention also includes an antibody thus modified. Examplesthereof can include a deletion mutant obtained by the deletion of 1 or 2amino acids at the heavy chain carboxyl terminus, and an amidated formof this deletion mutant (e.g., a heavy chain amidated at the prolineresidue at the carboxyl terminal site). However, the heavy chain carboxyterminus deletion mutant of the antibody according to the presentinvention is not limited to the types described above as long as thedeletion mutant maintains the ability to bind to the antigen and theeffector functions. Two heavy chains constituting the antibody accordingto the present invention may be any one type of heavy chain selectedfrom the group consisting of full length heavy chains and the heavychains of the deletion mutants described above, or may be a combinationof any two types selected therefrom. The quantitative ratio of eachdeletion mutant may be influenced by the type and culture conditions ofcultured mammalian cells producing the antibody according to the presentinvention. Examples of the main component of the antibody according tothe present invention can include two heavy chains, both of which lackone carboxy terminal amino acid residue. Specifically, a heavy chainconsisting of amino acid residues at positions 20 to 465 in a heavychain sequence shown in each of SEQ ID NOs: 27, 29, 39, 41, 43, 45, 62,64, 66, 68, and 70 of the Sequence Listing, or a heavy chain consistingof amino acid residues at positions 20 to 464 therein can also be usedin the antibody of the present invention.

Antibodies obtained by these methods can be evaluated for their bindingactivity against the antigen to select a suitable antibody. One exampleof another index for comparing antibody properties can include antibodystability. Differential scanning calorimetry (DSC) is a method capableof rapidly and accurately measuring a thermal denaturation midpoint(Tm), which serves as a good index for relative structural stability ofproteins. Tm values can be measured using DSC and compared to determinedistinctive heat stability. The storage stability of an antibody isknown to correlate with the heat stability of the antibody to someextent (Lori Burton, et al., Pharmaceutical Development and Technology(2007) 12, p. 265-273). A suitable antibody can be selected with heatstability as an index. Examples of other indexes for selecting theantibody can include high yields in appropriate host cells, and lowaggregation in an aqueous solution. For example, since it is not alwaystrue that an antibody having the highest yield exhibits the highest heatstability, an antibody most suitable for administration to humans has tobe selected by synthetic judgment based on the indexes mentioned above.

A method for obtaining a single chain immunoglobulin by linking the fulllength heavy and light chain sequences of the antibody via anappropriate linker is also known (Lee, H-S, et al., Molecular Immunology(1999) 36, p. 61-71; and Schirrmann, T. et al., mAbs (2010), 2 (1), p.73-76). Such a single chain immunoglobulin can be dimerized to therebymaintain a structure and activities similar to those of the antibody,which is originally a tetramer. Also, the antibody of the presentinvention may be an antibody that has a single heavy chain variableregion and has no light chain sequence. Such an antibody, called asingle domain antibody (sdAb) or nanobody, has actually been observed incamels and llamas and reported to maintain the ability to bind to theantigen (Muyldemans S. et al., Protein Eng. (1994) 7 (9), 1129-35; andHamers-Casterman C. et al., Nature (1993) 363 (6428), 446-8). Theseantibodies may be interpreted as one kind of antigen binding fragment ofthe antibody according to the present invention.

The antibody dependent cellular cytotoxic activity of the antibody ofthe present invention may be enhanced by adjusting the modification of asugar chain bound to the antibody. For example, methods described inWO99/54342, WO00/61739, and WO02/31140 are known as examples of such atechnique of adjusting a sugar chain modification of an antibody, thoughthis technique is not limited thereto.

In the case of preparing an antibody by temporarily isolating theantibody gene and then transferring the gene to an appropriate host, theappropriate host can be used in combination with an expression vector.Specific examples of the antibody gene can include a combination of agene encoding a heavy chain sequence and a gene encoding a light chainsequence of the antibody described in the present specification. For thetransformation of host cells, the heavy chain sequence gene and thelight chain sequence gene may be inserted into the same expressionvector or may be inserted into separate expression vectors. In the caseof using host eukaryotic cells, animal cells, plant cells, or eukaryoticmicrobes can be used. Examples of the animal cells can include mammaliancells, for example, monkey COS cells (Gluzman, Y., Cell (1981) 23, p.175-182, ATCC CRL-1650), mouse fibroblast NIH3T3 (ATCC No. CRL-1658),and dihydrofolate reductase deficient lines (Urlaub, G. and Chasin, L.A., Proc. Natl. Acad. Sci. U.S.A. (1980) 77, p. 4126-4220) of Chinesehamster ovary cells (CHO cells, ATCC CCL-61). In the case of usingprokaryotic cells, examples thereof can include E. coli and Bacillussubtilis. The antibody gene of interest is transferred to these cells bytransformation, and the transformed cells are cultured in vitro toobtain the antibody. Such a culture method may differ in yield dependingon the sequence of the antibody. An antibody that is easy to produce asa drug can be selected, by using its yield as an index, from amongantibodies having equivalent binding activity.

Examples of the isotype of the antibody of the present invention caninclude, but are not limited to, IgG (IgG1, IgG2, IgG3, and IgG4), IgM,IgA (IgA1 and IgA2), IgD, and IgE. The isotype can be preferably IgG orIgM, more preferably IgG1 or IgG2.

The antibody of the present invention may be an antigen binding fragmentof the antibody having the antigen binding site of the antibody, or amodified form thereof. The antibody fragment can be obtained by treatingthe antibody with a proteolytic enzyme such as papain or pepsin or byexpressing a genetically engineered antibody gene in appropriatecultured cells. Among such antibody fragments, a fragment that maintainsthe whole or a portion of the functions possessed by the full lengthmolecule of the antibody can be referred to as an antigen bindingfragment of the antibody.

Examples of the functions of the antibody can generally include antigenbinding activity, the activity of neutralizing the activity of theantigen, the activity of enhancing the activity of the antigen, antibodydependent cellular cytotoxic activity, complement dependent cytotoxicactivity, and complement dependent cellular cytotoxic activity. Thefunction possessed by the antigen binding fragment of the antibodyaccording to the present invention is binding activity against Orai1 andis preferably the activity of inhibiting the activation of T cells, morepreferably the activity of inhibiting the production of IL-2 and/orinterferon γ by T cells.

Examples of the fragment of the antibody can include Fab, F(ab′)2, Fv,single chain Fv (scFv) comprising heavy and light chain Fvs linked viaan appropriate linker, diabodies, linear antibodies, and multispecificantibodies formed from antibody fragments. The fragment of the antibodyalso includes Fab′, which is a monovalent fragment of antibody variableregions obtained by the treatment of F(ab′)2 under reducing conditions.

The antibody of the present invention may be a multispecific antibodyhaving specificity for at least two different types of antigens. Such amolecule usually binds to two types of antigens (i.e., a bispecificantibody). The “multispecific antibody” according to the presentinvention encompasses an antibody having specificity for more types(e.g., 3 types) of antigens.

The multispecific antibody of the present invention may be an antibodyconsisting of a full length antibody, or may be a fragment of such anantibody (e.g., F(ab′)2 bispecific antibody). The bispecific antibodymay be prepared by linking the heavy and light chains (HL pairs) of twotypes of antibodies, or may be prepared by fusing hybridomas producingdifferent monoclonal antibodies to prepare fusion cells producing thebispecific antibody (Millstein et al., Nature (1983) 305, p. 537-539).

The antibody of the present invention may be a single chain antibody(single chain Fv; also referred to as “scFv”). The scFv is obtained bylinking the heavy and light chain variable regions of the antibody via apolypeptide linker (Pluckthun, The Pharmacology of MonoclonalAntibodies, 113 (Rosenberg and Moore ed., Springer Verlag, New York, p.269-315 (1994); and Nature Biotechnology (2005), 23, p. 1126-1136).Also, a biscFv fragment prepared by linking two scFvs via a polypeptidelinker can also be used as a bispecific antibody.

The method for preparing the scFv is well known in the art (see e.g.,U.S. Pat. Nos. 4,946,778, 5,260,203, 5,091,513, and 5,455,030). In thisscFv, the heavy chain variable region and the light chain variableregion are linked via a linker, preferably a polypeptide linker, thatprevents them from forming a conjugate (Huston, J. S. et al., Proc.Natl. Acad. Sci. U.S.A. (1988), 85, p. 5879-5883). The heavy chainvariable region and the light chain variable region in the scFv may bederived from the same antibody or may be derived from differentantibodies. For example, an arbitrary single chain peptide consisting of12 to 19 residues is used as the polypeptide linker that links thesevariable regions.

In order to obtain DNA encoding the scFv, each DNA portion encoding thewhole or desired amino acid sequence in the sequences of DNA encodingthe heavy chain or heavy chain variable region of the antibody and DNAencoding the light chain or light chain variable region thereof, is usedas a template and amplified by PCR using a primer pair flanking bothends of the template. Subsequently, DNA encoding the polypeptide linkermoiety is further amplified in combination with a primer pair flankingboth ends of the DNA so that the obtained fragment can be linked at itsends to the heavy and light chain DNAs, respectively.

Once the DNA encoding the scFv is prepared, an expression vectorcontaining the DNA and a host transformed with the expression vector canbe obtained according to routine methods. In addition, the host can beused to obtain the scFv according to routine methods. These antibodyfragments can be produced by a host in the same way as above byobtaining and expressing the gene.

The antibody of the present invention may be multimerized to therebyenhance its affinity for the antigen. Antibodies of the same type may bemultimerized, or a plurality of antibodies recognizing a plurality ofepitopes, respectively, of the same antigen may be multimerized.Examples of a method for multimerizing these antibodies can include thebinding of two scFvs to an IgG CH3 domain, the binding thereof tostreptavidin, and the introduction of a helix-turn-helix motif.

The antibody of the present invention may be a polyclonal antibody whichis a mixture of plural types of anti-Orai1 antibodies differing in aminoacid sequence. One example of the polyclonal antibody can include amixture of plural types of antibodies differing in CDRs. An antibodyobtained by culturing a mixture of cells producing different antibodies,followed by purification from the cultures can be used as such apolyclonal antibody (see WO2004/061104).

An antibody conjugated with any of various molecules such aspolyethylene glycol (PEG) can also be used as a modified form of theantibody.

The antibody of the present invention may further be any of theconjugates formed by these antibodies with other drugs(immunoconjugates). Examples of such an antibody can include theantibody conjugated with a radioactive material or a compound having apharmacological effect (Nature Biotechnology (2005) 23, p. 1137-1146).

The obtained antibody can be purified until homogeneous. Usual proteinseparation and purification methods can be used for the separation andpurification of the antibody. The antibody can be separated and purifiedby appropriately selected or combined approach(es), for example, columnchromatography, filtration through a filter, ultrafiltration, saltingout, dialysis, preparative polyacrylamide gel electrophoresis, and/orisoelectric focusing (Strategies for Protein Purification andCharacterization: A Laboratory Course Manual, Daniel R. Marshak et al.eds., Cold Spring Harbor Laboratory Press (1996); and Antibodies: ALaboratory Manual. Ed Harlow and David Lane, Cold Spring HarborLaboratory (1988)), though the separation and purification method is notlimited thereto.

Examples of such chromatography can include affinity chromatography, ionexchange chromatography, hydrophobic chromatography, gel filtrationchromatography, reverse phase chromatography, and adsorptionchromatography. These chromatography approaches can be carried out usingliquid chromatography such as HPLC or FPLC. Examples of the column foruse in the affinity chromatography can include protein A columns andprotein G columns. Examples of the protein A columns can include HyperD, POROS, and Sepharose F. F. (Pharmacia Corp.). Also, the antibody maybe purified by use of its binding activity against the antigen using anantigen immobilized carrier.

3. Drug Containing Anti-Orai1 Antibody

An antibody neutralizing the biological activity of Orai1 can beobtained from among the anti-Orai1 antibodies obtained by the methodsdescribed in the preceding paragraph “2. Production of anti-Orai1antibody”. Such an antibody, neutralizing the biological activity ofOrai1, can inhibit the in vivo biological activity of Orai1, i.e., theactivation of the calcium release activated calcium channels (CRACchannels) of Orai1-expressing cells typified by T cells and mast cellsand as such, can be pharmaceutically used as a therapeutic and/orprophylactic agent for diseases caused by the activation of the CRACchannels of these cells.

The diseases or conditions caused by CRAC channel activation includetransplant rejection, immune-related diseases, allergic diseases,inflammatory diseases, thrombosis, and cancers, etc.

Examples of the treatment and/or prevention of transplant rejectioninclude the treatment and/or prevention of rejection response and hostversus graft reaction to the transplantation of an organ or a tissuesuch as the heart, the kidney, the liver, bone marrow, or skin, andgraft versus host disease caused by the transplantation of hematopoieticcells (bone marrow, peripheral blood, umbilical cord blood, etc.).

Examples of immune-related diseases include connective tissue ormusculoskeletal diseases (rheumatoid arthritis, ankylosing spondylitis,systemic lupus erythematosus, scleroderma, polymyositis,dermatomyositis, etc.), hematological diseases (aplastic anemia,idiopathic thrombocytopenic purpura, etc.), gastrointestinal diseases(Crohn disease, ulcerative colitis, etc.), neurological diseases(multiple sclerosis, myasthenia gravis, etc.), ophthalmic diseases(uveitis, etc.), vascular diseases (Behcet's disease, Wegener'sgranulomatosis, etc.), epidermal diseases (psoriasis, pemphigus,leukoderma, etc.), and endocrine diseases (type 1 diabetes mellitus,autoimmune thyroiditis, Graves' disease, Hashimoto's disease, etc.).

Examples of the allergic diseases include atopic dermatitis, asthma,anaphylaxis, anaphylactoid reaction, food allergy, rhinitis, otitismedia, drug reaction, insect bite reaction, reaction to plants, latexallergy, conjunctivitis, and urticaria.

Examples of the inflammatory diseases include inflammatory renaldiseases (glomerulonephritis, nephrosis, etc.), inflammatory pulmonarydiseases (chronic obstructive pulmonary disease, cystic fibrosis,interstitial pneumonia, etc.), inflammatory bowel diseases (ulcerativecolitis, ileitis, etc.), inflammatory hepatic diseases (autoimmunehepatitis, viral hepatitis, etc.), inflammatory cardiac diseases(myocarditis, ischemic heart disease, atherosclerosis, etc.),inflammatory skin diseases (contact dermatitis, eczema, etc.),inflammatory eye diseases (trachoma, endophthalmitis, etc.),inflammatory central nervous diseases (meningitis, encephalomyelitis,autoimmune encephalitis, etc.), inflammatory joint diseases (arthritis,osteoarthritis, etc.), and systemic inflammations (sepsis, bleeding,hypersensitivity, shock symptoms attributed to cancer chemotherapy orthe like, etc.).

Examples of cases in which the antiplatelet or antithrombotic activityis useful for treatment and/or prevention are myocardial infarction,stroke, ischemic heart diseases, and thrombosis.

Examples of the treatment of the cancers include breast cancer, lungcancer, skin cancer, and leukemia.

Further examples of the diseases that can be treated by the antibody ofthe present invention include: pathological conditions involving mastcells and basophils, such as mast cell leukemia, mastocytosis,basophilic leukemia, and endometriosis; and tubular aggregate myopathy,Stormorken syndrome, rheumatoid arthritis, ankylosing spondylitis, andatopic dermatitis, which develop or whose risk of development isincreased by the genetic hyperfunction of CRAC channels.

Examples of the anti-Orai1 antibody as the drug can include humanizedantibodies prepared from the R118 antibody and/or the R198 antibody, andCDR engineered forms thereof.

The in vitro neutralizing activity of the anti-Orai1 antibody againstthe biological activity of Orai1 can be measured on the basis of, forexample, the inhibitory activity against the activation of T cellsexpressing Orai1. For example, the anti-Orai1 antibody is added atvarying concentrations to human T cell-derived cell line Jurkat cells,and the inhibitory activity against IL-2 release from the Jurkat cellsstimulated with PMA and A23187 can be measured. Also, the anti-Orai1antibody is added at varying concentrations to human peripheral bloodmononuclear cells (PBMC), and the inhibitory activity against IL-2 andinterferon γ release from PBMC stimulated with PMA and A23187 can bemeasured.

It is an experimentally proven fact, and widely recognized, that thecells responsible for the development of graft versus host disease are Tcells. When transplanted T cells recognize the recipient as foreignmatter, self-propagation based on interleukin 2 (IL-2) produced bythemselves, and the release of inflammatory cytokines such as interferongamma (IFN-γ) by activation cause a systemic immunological inflammationreaction, resulting in the development of graft versus host disease.Thus, the inhibition of the production of these cytokines leads to theprevention or treatment of graft versus host disease, while theusefulness of the anti-Orai1 antibody as a therapeutic drug can bedetermined by using its inhibitory activity as an index.

Preferred examples of the antibody according to the present inventioncan include an antibody or an antigen binding fragment of the antibodywhich specifically binds to the amino acid sequence represented by SEQID NO: 2, wherein the concentration at which the amount of IL-2 releasedfrom Jurkat cells treated with PMA and A23187 is inhibited by 50% is 80ng/mL or lower. More preferred examples of this antibody can include theantibody or the antigen binding fragment of the antibody, wherein theconcentration at which the amount of IL-2 released from Jurkat cellstreated with PMA and A23187 is inhibited by 50% is 10 ng/mL or lower.The antibody of the present invention also includes an antibody or anantigen binding fragment of the antibody, wherein the concentration atwhich the amount of IL-2 released from Jurkat cells treated with PMA andA23187 is inhibited by 80% is 60000 ng/mL or lower, and an antibody oran antigen binding fragment of the antibody, wherein the concentrationat which the amount of IL-2 released from Jurkat cells treated with PMAand A23187 is inhibited by 80% is 200 ng/mL or lower.

Alternative preferred examples of the antibody according to the presentinvention can include an antibody or an antigen binding fragment of theantibody which specifically binds to the amino acid sequence representedby SEQ ID NO: 2, wherein the concentration at which the amount of IL-2released from human PBMC treated with PMA and A23187 is inhibited by 50%is 100 ng/mL or lower. More preferred examples of this antibody caninclude the antibody or the antigen binding fragment of the antibody,wherein the concentration at which the amount of IL-2 released fromhuman PBMC treated with PMA and A23187 is inhibited by 50% is 20 ng/mLor lower. The antibody of the present invention also includes anantibody or an antigen binding fragment of the antibody, wherein theconcentration at which the amount of IL-2 released from human PBMCtreated with PMA and A23187 is inhibited by 80% is 17000 ng/mL or lower,and an antibody or an antigen binding fragment of the antibody, whereinthe concentration at which the amount of IL-2 released from human PBMCtreated with PMA and A23187 is inhibited by 80% is 400 ng/mL or lower.

Further alternative preferred examples of the antibody according to thepresent invention can include an antibody or an antigen binding fragmentof the antibody which specifically binds to the amino acid sequencerepresented by SEQ ID NO: 2, wherein the concentration at which theamount of IFN-γ released from human PBMC treated with PMA and A23187 isinhibited by 50% is 800 ng/mL or lower. More preferred examples of thisantibody can include the antibody or the antigen binding fragment of theantibody, wherein the concentration at which the amount of IFN-γreleased from human PBMC treated with PMA and A23187 is inhibited by 50%is 40 ng/mL or lower. The antibody of the present invention alsoincludes an antibody or an antigen binding fragment of the antibody,wherein the concentration at which the amount of IFN-γ released fromhuman PBMC treated with PMA and A23187 is inhibited by 80% is 300000ng/mL or lower, and an antibody or an antigen binding fragment of theantibody, wherein the concentration at which the amount of IFN-γreleased from human PBMC treated with PMA and A23187 is inhibited by 80%is 2000 ng/mL or lower.

The in vivo therapeutic or prophylactic effect of the anti-Orai1antibody on graft versus host disease in a laboratory animal can beconfirmed, for example, by measuring the inhibition of weight loss in ahuman PBMC transplanted mouse graft versus host disease model.Specifically, NOG or NSG mice, which are severe combined immunodeficientmice, are irradiated with X-rays of 2.0 Gy. On the next day, 200 μL of aPBS solution containing 15,000,000 to 50,000,000 cells of human PBMC permL is transplanted to each mouse via the tail vein. An X-ray irradiatedmouse group that has not received human PBMC is used as a non-graftversus host disease group, and a human PBMC transplanted group givenonly a vehicle solution for the antibody is used as a graft versus hostdisease group. Before or after the human PBMC transplantation, theanti-Orai1 antibody is administered either intravenously to the tail orintraperitoneally to measure the inhibitory effect on weight loss in thegraft versus host disease group.

In addition, the therapeutic or prophylactic effect of the anti-Orai1antibody on various diseases can also be confirmed by the following invivo evaluation systems using a human Orai1 knock-in mouse.

For the effect on dermatitis, a protein antigen solution isintraperitoneally or intravenously administered to a mouse, and after 2weeks, the antigen is injected thereto as a booster. Then, the sameprotein antigen solution as above is repetitively applied to the ear orthe back 3 to 6 times at 3 day to 2 week intervals to cause dermatitis.The effect on dermatitis is evaluated by comparing the auriclethickness, the macroscopic score of dermatitis in the back, theconcentrations of the antibody, cytokines, or serum biomarkers in bloodor tissues, and the growth activity, cytokine producing ability, orsurface antigens of cells obtained from the skin, peripheral blood, thethymus, the spleen, the lymph node, or the bone marrow between ananti-Orai1 antibody group and a non-administration group.

For the effect on pruritus, a mite antigen cream is repetitively appliedto the auricle or the back 3 to 6 times at 3 day to 2 week intervals, ora hapten is applied to the auricle, the abdominal region, or the backevery day to once a week, or a pruritus inducing substance isadministered intracutaneously to the auricle, subcutaneously to theback, or by the intrathecal route. Pruritic action induced by such amethod is quantified by measuring the number of pruritic events usingmagnets attached to the dorsum of both feet of the mouse and a pruriticaction measurement apparatus, or by examining pathological signs in theskin, peripheral blood, or spinal cord tissues. The effect on pruritusis evaluated by comparing the obtained results between an anti-Orai1antibody group and a non-administration group.

For the effect on psoriasis, imiquimod is applied to both sides or oneside of the auricle and the shaved back, or a zymosan suspension isintraperitoneally administered, or a cytokine such as IL-23 isintracutaneously administered to one side of the mouse auricle.Psoriatic dermatitis induced by such a method is quantified by theexamination of the weight and thickness of an inflammation site, themyeloperoxidase activity of neutrophils infiltrated into the site, theflow cytometry analysis of the infiltrated cells, gene analysis,cytokine concentration measurement, etc. The effect on psoriasis isevaluated by comparing the obtained results between an anti-Orai1antibody group and a non-administration group.

For the effect on multiple sclerosis, a solution of myelinoligodendrocyte glycoprotein or a partial peptide antigen thereof isemulsified by mixing with an aqueous solution of a Freund's completeadjuvant in equal amounts. This emulsion is intracutaneouslyadministered to the flank or abdominal region of a mouse. Then, anaqueous pertussis toxin solution is administered to the tail vein. Aftera few days, the pertussis toxin solution is further administered againto the tail vein to induce experimental encephalomyelitis. Paralysissymptoms that develop after 1 week to 2 weeks of the experiment andexpand from the tail to the lower legs and the anterior limbs are scoredby macroscopic observation. The effect on multiple sclerosis isevaluated by comparing the obtained results between an anti-Orai1antibody group and a non-administration group.

For the effect on arthritis, an emulsion obtained by mixing bovine typeII collagen and a Freund's complete adjuvant is intracutaneouslyadministered to the tail base of a mouse. After 2 to 3 weeks, the sameadministration as above is carried out. Then, the effect on arthritis isevaluated by comparing the score of joint swelling, the concentrationsof the antibody, cytokines, or serum biomarkers in blood or tissues, thegrowth activity, cytokine producing ability, or surface antigens ofcells obtained from the skin, peripheral blood, the thymus, the spleen,the lymph node, or the bone marrow, etc. between an anti-Orai1 antibodygroup and a non-administration group.

For the effect on colitis, trinitrobenzenesulfonic acid is administeredinto the intestinal tract of a mouse fasted for 24 hours, or a mouse isallowed to drink freely an aqueous solution containing 1 to 10% sodiumdextran sulfate from a water feed bottle for 4 days to 2 weeks, orCD4+CD25-CD45RBhi T-cells collected and purified from the lymph node andthe spleen of a human Orai1 knock-in mouse are intraperitoneallytransplanted into a Rag2−/− mouse. The effect on colitis induced by sucha method is evaluated by comparing the body weight during theobservation period, the degree of thickening of the intestinal tract,the number and size of polyps, and pathological signs examined byautopsy after the completion of the test, the concentrations of theantibody, cytokines, or serum biomarkers in blood or tissues, the growthactivity, cytokine producing ability, or surface antigens of cellsobtained from the intestinal tract, peripheral blood, the thymus, thespleen, the lymph node, or the bone marrow, etc. between an anti-Orai1antibody group and a non-administration group.

For the effect on systemic lupus erythematosus, egg albumin or anothernon-stimulating antigen is intraperitoneally or subcutaneouslyadministered a maximum of 15 times at 5 to 10 day intervals to inducesystemic lupus erythematosus-like symptoms. The effect on systemic lupuserythematosus is evaluated by comparing the concentrations of theantibody, cytokines, or serum biomarkers in blood or tissues collectedover time during the observation period, the antibody titer or biomarkerconcentration in urine, symptoms induced in an untreated mouse by thetransplantation of cells prepared from an organ such as the spleen orthe lymph node collected after the completion of the test, etc., betweenan anti-Orai1 antibody group and a non-administration group.

For the effect on hepatitis, D-galactosamine is intraperitoneallyadministered either alone or in combination with lipopolysaccharide to amouse, or concanavalin A is intravenously administered alone to thetail. The effect on hepatitis induced by such a method is evaluated bycomparing GOT and GPT concentrations in blood collected 1 hour to 1 weekafter the administration of the causative substance, and thehistopathological conditions of liver lesions between an anti-Orai1antibody group and a non-administration group.

For the effect on the graft survival rate in bone marrow celltransplantation or the prophylactic effect on graft versus host disease,cells within the bone marrow collected from the thigh bone or theshinbone of a human Orai1 knock-in mouse are transplanted to an X-rayirradiated recipient mouse either alone or in combination with spleencells collected from the spleen of the human Orai1 knock-in mouse. Theeffect on the graft survival rate or the prophylactic effect isevaluated by comparing change in body weight or survival rates for 4 to16 weeks, the concentrations of the antibody, cytokines, or serumbiomarkers in blood or tissues at the completion of the test, and thesurface antigens, growth activity, or cytokine producing ability ofcells obtained from the intestinal tract, peripheral blood, the thymus,the spleen, the lymph node, or the bone marrow between an anti-Orai1antibody group and a non-administration group.

For the effect on the graft survival rate of a transplanted organ, theskin collected from the tail base of a host mouse is fixed to thepanniculus carnosus exposed by cutting the skin in the back of a humanOrai1 knock-in mouse. The size of the transplant and its status ofengraftment are scored for 4 to 16 weeks after transplantation. Theeffect on the graft survival rate is evaluated by comparing the obtainedresults between an anti-Orai1 antibody group and a non-administrationgroup.

The thus-obtained antibody, which neutralizes the biological activity ofOrai1, is useful as a drug, particularly, as an antibody for theprevention or treatment of transplant rejections, immune-relateddiseases, allergic diseases, inflammatory diseases, thrombosis, orcancers, etc.

As one example, the anti-Orai1 antibody can be administered either aloneor in combination with at least one additional therapeutic agent for thetreatment or prevention of transplant rejections, immune-relateddiseases, allergic diseases, inflammatory diseases, thrombosis, orcancers. Examples of the additional therapeutic agent that can beadministrated in combination with the anti-Orai1 antibody can include,but are not limited to, antifolates, calcineurin inhibitors, adrenalcortical steroids, antithymocyte globulins, nucleic acidantimetabolites, nucleic acid synthesis inhibitors, biologics targetingcell surface antigens, and biologics targeting cytokines or cytokinereceptors.

Specific examples of these therapeutic agents can include: methotrexateas the antifolate; cyclosporine and tacrolimus as the calcineurininhibitors; methylprednisolone as the adrenal cortical steroid;cyclophosphamide as the nucleic acid synthesis inhibitor; Zetbulin,lymphoglobuline, and thymoglobulin as the antithymocyte globulins;mycophenolate mofetil as the nucleic acid antimetabolite; alemtuzumaband rituximab as the biologics targeting cell surface antigens; andinfliximab, etanercept, and rituximab as the biologics targetingcytokines or cytokine receptors.

Depending on the conditions of transplant rejections, immune-relateddiseases, allergic diseases, inflammatory diseases, thrombosis, orcancers or the goal of treatment and/or prevention thereof, 2, 3, ormore types of additional therapeutic agents may be administered, andthese additional therapeutic agents can be enclosed in the samepreparation and administered at the same time. The additionaltherapeutic agent and the anti-Orai1 antibody may be enclosed in thesame preparation and administered at the same time. Alternatively, theanti-Orai1 antibody and the additional therapeutic agent may be enclosedin separate preparations and administered at the same time. Furthermore,the additional therapeutic agent and the anti-Orai1 antibody may beseparately administered in a staggered manner. Specifically, thetherapeutic agent containing the anti-Orai1 antibody or the antigenbinding fragment of the antibody as an active ingredient may beadministered after administration of the additional therapeutic agent,or the additional therapeutic agent may be administered afteradministration of the therapeutic agent containing the anti-Orai1antibody or the antigen binding fragment of the antibody as an activeingredient. In the case of administration for gene therapy, a gene of aproteinous therapeutic agent and the gene of the anti-Orai1 antibody canbe inserted downstream of separate promoter regions or the same promoterregion and introduced into separate vectors or the same vector.

The anti-Orai1 antibody or the fragment thereof can be conjugated with atherapeutic agent to produce a targeted drug conjugate described in M.C. Garnet, “Targeted drug conjugates: principles and progress”, AdvancedDrug Delivery Reviews, (2001) 53, 171-216. For this purpose, theantibody molecule as well as any antibody fragment is applicable as longas the antibody fragment does not completely lose the property ofrecognizing T cells. Examples of the fragment can include Fab, F(ab′)2,and Fv fragments. As such, the antibody and the fragment can be used inthe present invention. The conjugation pattern between the anti-Orai1antibody or the fragment of the antibody and the therapeutic agent canbe any of various patterns described in M. C. Garnet, “Targeted drugconjugates: principles and progress”, Advanced Drug Delivery Reviews,(2001) 53, 171-216, G. T. Hermanson, “Bioconjugate Techniques”, AcademicPress, California (1996), Putnam and J. Kopecek, “Polymer Conjugateswith Anticancer Activity”, Advances in Polymer Science (1995) 122,55-123, etc. Specific examples thereof can include a pattern in whichthe anti-Orai1 antibody and the therapeutic agent are conjugateddirectly in a chemical manner or via a spacer such as an oligopeptide,and a pattern in which the anti-Orai1 antibody and the therapeutic agentare conjugated via an appropriate drug carrier. Examples of the drugcarrier can include liposomes and water soluble polymers. Examples ofsuch a pattern mediated by these drug carriers can more specificallyinclude a pattern in which the antibody and the therapeutic agent areenclosed in a liposome by the conjugation of the liposome and theantibody, and a pattern in which the therapeutic agent is conjugatedwith a water soluble polymer (a compound having a molecular weight inthe order of 1000 to 100,000) directly in a chemical manner or via aspacer such as an oligopeptide while the antibody is conjugated with thewater soluble polymer. The conjugation of the antibody (or the fragment)with the therapeutic agent or the drug carrier (e.g., liposome and watersoluble polymer) can be carried out by a method well known to thoseskilled in the art, for example, a method described in G. T. Hermanson,“Bioconjugate Techniques”, Academic Press, California (1996), and Putnamand J. Kopecek, “Polymer Conjugates with Anticancer Activity”, Advancesin Polymer Science (1995) 122, 55-123. The enclosure of the therapeuticagent in the liposome can be carried out by a method well known to thoseskilled in the art, for example, a method described in D. D. Lasic,“Liposomes: From Physics to Applications”, Elsevier Science PublishersB. V., Amsterdam (1993), etc. The conjugation of the therapeutic agentwith the water soluble polymer can be carried out by a method well knownto those skilled in the art, for example, a method described in D.Putnam and J Kopecek, “Polymer Conjugates with Anticancer Activity”,Advances in Polymer Science (1995) 122, 55-123. The conjugate of theantibody (or the fragment) and a proteinous therapeutic agent (or thefragment) can be prepared by any of the methods described above as wellas genetic engineering methods well known to those skilled in the art.

The present invention also provides a pharmaceutical compositioncomprising a therapeutically and/or prophylactically effective amount ofthe anti-Orai1 antibody and a pharmaceutically acceptable diluent,vehicle, solubilizer, emulsifier, preservative, and/or additive.

The present invention also provides a pharmaceutical compositioncomprising a therapeutically and/or prophylactically effective amount ofthe anti-Orai1 antibody, a therapeutically and/or prophylacticallyeffective amount of at least one therapeutic agent, and apharmaceutically acceptable diluent, vehicle, solubilizer, emulsifier,preservative, and/or additive. Examples of the therapeutic agent caninclude, but are not limited to the aforementioned antifolates,calcineurin inhibitors, adrenal cortical steroids, antithymocyteglobulins, nucleic acid antimetabolites, nucleic acid synthesisinhibitors, biologics targeting cell surface antigens, and biologicstargeting cytokines or cytokine receptors.

It is preferred that the pharmaceutically acceptable substance used inthe pharmaceutical composition of the present invention should benontoxic to a recipient of the pharmaceutical composition, preferably interms of a dose or an administered concentration.

The pharmaceutical composition of the present invention can containpharmaceutical materials for changing or maintaining pH, osmoticpressure, viscosity, transparency, color, Isotonicity, sterility,stability, solubility, sustained release, absorbability, orpermeability. Examples of the pharmaceutical materials can include, butare not limited to, the following: amino acids such as glycine, alanine,glutamine, asparagine, arginine, and lysine; antimicrobial agents;antioxidants such as ascorbic acid, sodium sulfate, and sodiumbisulfite; buffers such as phosphate, citrate, or borate buffers, sodiumbicarbonate, and Tris-HCl solutions; fillers such as mannitol andglycine; chelating agents such as ethylenediaminetetraacetic acid(EDTA); complexing agents such as caffeine, polyvinylpyrrolidine,β-cyclodextrin, and hydroxypropyl-β-cyclodextrin; bulking agents such asglucose, mannose, and dextrin; other carbohydrates such asmonosaccharides and disaccharides; coloring agents; corrigents;diluents; emulsifiers; hydrophilic polymers such aspolyvinylpyrrolidine; low molecular weight polypeptides; salt formingcounterions; antiseptics such as benzalkonium chloride, benzoic acid,salicylic acid, thimerosal, phenethyl alcohol, methylparaben,propylparaben, chlorhexidine, sorbic acid, and hydrogen peroxide;solvents such as glycerin, propylene glycol, and polyethylene glycol;sugar alcohols such as mannitol and sorbitol; suspending agents;surfactants such as sorbitan ester, polysorbates such as polysorbate 20and polysorbate 80, triton, tromethamine, lecithin, and cholesterol;stability enhancers such as sucrose and sorbitol; elasticity enhancerssuch as sodium chloride, potassium chloride, mannitol, and sorbitol;transport agents; excipients; and/or pharmaceutical additives. Theamount of these pharmaceutical materials added is preferably 0.01 to 100times, particularly, 0.1 to 10 times the weight of the anti-Orai1antibody. A suitable recipe for the pharmaceutical composition in apreparation can be appropriately determined by those skilled in the artaccording to an applicable disease, an applicable administration route,etc.

The excipient or the vehicle in the pharmaceutical composition may beliquid or solid. Appropriate excipients or vehicles may be othermaterials usually used in injectable water, physiological saline,artificial cerebrospinal fluids, and parenteral administration. Neutralphysiological saline or physiological saline containing serum albuminmay be used as a vehicle. The pharmaceutical composition can contain aTris buffer of pH 7.0 to 8.5, an acetate buffer of pH 4.0 to 5.5, or acitrate buffer of pH 3.0 to 6.2. These buffers can also contain sorbitolor other compounds. Examples of the pharmaceutical composition of thepresent invention can include a pharmaceutical composition comprisingthe anti-Orai1 antibody, and a pharmaceutical composition comprising theanti-Orai1 antibody and at least one therapeutic agent. Thepharmaceutical composition of the present invention is prepared in theform of a freeze dried product or a liquid as a drug having a selectedrecipe and a required purity. The pharmaceutical composition comprisingthe anti-Orai1 antibody, or the pharmaceutical composition comprisingthe anti-Orai1 antibody and at least one therapeutic agent can also beformed as a freeze dried product using an appropriate excipient such assucrose.

The pharmaceutical composition of the present invention may be preparedfor parenteral administration or may be prepared for absorption in thedigestive tract through an oral route. The recipe and concentration ofthe preparation can be determined according to the administrationmethod. The higher the affinity of the anti-Orai1 antibody contained inthe pharmaceutical composition of the present invention for Orai1, i.e.,a lower dissociation constant (Kd value) for Orai1, the lower the doseof the anti-Orai1 antibody which can show efficacy in a human.Therefore, the dose of the pharmaceutical composition of the presentinvention to a human can also be determined on the basis of this result.The dose for the administration of the human type anti-Orai1 antibody toa human is approximately 0.1 to 100 mg/kg, which can be administeredonce per 1 to 180 days.

Examples of the form of the pharmaceutical composition of the presentinvention can include injections including intravenous drips,suppositories, transnasal formulations, sublingual formulations, andtransdermal absorption formulations.

Although most approved antibody preparations are intravenouslyadministered, subcutaneous administration is often more preferred inmedical practice. In such a case, the volume is limited to 1.0 to 1.5mL. Therefore, an antibody solution having a high concentration isrequired depending on the dose. However, since a higher concentrationincreases the viscosity of the drug solution, there may exist asituation in which the drug solution cannot be injected by use of aninjection needle having a thickness routinely used, due to its highviscosity. In short, in the case of selecting an injection as the formof the pharmaceutical composition, the low viscosity is an importantproperty that should be given the highest priority. Thus, a suitableantibody can be selected with the viscosity as an index.

EXAMPLES

Hereinafter, the present invention will be specifically described withreference to Examples. However, the present invention is not intended tobe limited by them. Each procedure related to gene manipulation in theExamples below was performed according to the methods described in“Molecular Cloning” (Sambrook, J., Fritsch, E. F. and Maniatis, T., ColdSpring Harbor Laboratory Press, 1989), or using commercially availablereagents or kits according to the instruction manuals of the commercialproducts, unless otherwise specified.

[Example 1] Preparation of Rat Anti-Human Orai1 Antibody

1)-1 Immunization

1)-1-1 Construction of Human Orai1 Expression Vector (pcDNA3.1-hOrai1)

Ultimate ORF clone (Clone No. IOH40869, Life Technologies Corp.) clonedin pDONR221 (Life Technologies Corp.) was purchased and used as the genesequence of human Orai1. The gene sequence is shown in SEQ ID NO: 1 ofthe Sequence Listing, and the amino acid sequence is shown in SEQ ID NO:2 of the Sequence Listing. Also, pcDNA3.1(+) was modified into adestination vector with Gateway Vector Conversion System (LifeTechnologies Corp.) to prepare pcDNA3.1-DEST. The gene sequence wasrecombined with pcDNA3.1-DEST within the att sequence using Gateway LRClonase Enzyme mix (Life Technologies Corp.) to prepare a human Orai1expression vector pcDNA3.1-hOrai1. EndoFree Plasmid Giga Kit (QiagenN.V.) was used in the large scale preparation of the human Orai1expression vector.

1)-1-2 Rat Immunization

Female WKY/Izm rats (Japan SLC, Inc.) were used in immunization. First,both lower legs of each rat were pretreated with hyaluronidase(Sigma-Aldrich Corp.), and then, pcDNA3.1-hOrai1 was intramuscularlyinjected to these sites. Subsequently, in vivo electroporation wascarried out at the sites using ECM830 (BTX) and a two-needle electrode.After repeating of similar in vivo electroporation once every two weeks,the lymph node of the rat was collected and used in hybridomapreparation.

1)-2 Hybridoma Preparation

The lymph node cells were electrically fused with mouse myelomaSP2/0-ag14 cells using Hybrimune Hybridoma Production System (Cyto PulseSciences Inc.). The fused cells were diluted with ClonaCell-HY SelectionMedium D (StemCell Technologies Inc.) and cultured. Hybridoma coloniesthat appeared were recovered to prepare monoclonal hybridomas. Eachhybridoma colony recovered was cultured, and the obtained hybridomaculture supernatant was used to screen for a hybridoma producing theanti-human Orai1 antibody.

1)-3 Primary Screening by Cell-ELISA

1)-3-1 Preparation of Antigen Gene Expressing Cell for Cell-ELISA

HEK293 cells were prepared at 7.5×10⁵ cells/mL in a DMEM mediumcontaining 10% FBS. The cells were transfected with pcDNA3.1-hOrai1 orpcDNA3.1-DEST as a control according to transfection procedures usingLipofectamine 2000, dispensed at 50 μl/well to a 96-well plate (CorningInc.), and cultured at 37° C. for two nights under 5% CO₂ conditions ina DMEM medium containing 10% FBS. The obtained transfected cells wereused in the attached state in Cell-ELISA.

1)-3-2 Cell-ELISA

After removal of the culture supernatant from the HEK293 cellstransfected with the expression-vector prepared in Example 1)-1-1, eachhybridoma culture supernatant was added to the pcDNA3.1-hOrai1 orpcDNA3.1-DEST transfected HEK293 cells, and the plate was incubated at4° C. for 1 hour. The cells in the wells were washed once with PBScontaining 5% FBS. Then, Anti-Rat IgG-Peroxidase antibody produced inrabbit (Sigma-Aldrich Corp.) diluted 500-fold with PBS containing 5% FBSwas added thereto, and the plate was incubated at 4° C. for 1 hour. Thecells in the wells were washed 6 times with PBS containing 5% FBS. Then,an OPD chromogenic solution (OPD solution (o-phenylenediaminedihydrochloride (Wako Pure Chemicals Industries, Ltd.) and H₂O₂dissolved at concentrations of 0.4 mg/mL and 0.6% (v/v), respectively,in 0.05 M trisodium citrate and 0.1 M disodium hydrogen phosphatedodecahydrate, pH 4.5)) was added thereto at 25 μL/well. Color reactionwas performed with occasional stirring and stopped by the addition of 1M HCl at 25 μL/well. Then, the absorbance was measured at 490 nm using aplate reader (ENVISION; PerkinElmer, Inc.). In order to select ahybridoma producing an antibody specifically binding to human Orai1expressed on the cell membrane surface, hybridomas that yielded aculture supernatant exhibiting higher absorbance for the pcDNA3.1-hOrai1expression-vector-transfected HEK293 cells compared with the controlpcDNA3.1-DEST transfected HEK293 cells were selected as anti-human Orai1antibody positive hybridomas.

1)-4 Secondary Screening by Flow Cytometry

1)-4-1 Preparation of Antigen Gene Expressing Cell for Flow CytometryAnalysis

HEK293T cells were inoculated at 5×10⁴ cells/cm² onto a 225 cm² flaskand cultured overnight at 37° C. under 5% CO₂ conditions in a DMEMmedium containing 10% FBS. On the next day, the HEK293T cells weretransfected with pcDNA3.1-hOrai1 or pcDNA3.1-DEST as a control usingLipofectamine 2000 and further cultured at 37° C. for two nights under5% CO₂ conditions. On the next day, the expression vector transfectedHEK293T cells were treated with TrypLE Express (Life TechnologiesCorp.), washed with DMEM containing 10% FBS, and then suspended in PBScontaining 5% FBS. The obtained cell suspension was used in flowcytometry analysis.

1)-4-2 Flow Cytometry Analysis

The human Orai1 binding specificity of the antibody produced by eachhybridoma confirmed to be positive by Cell-ELISA in Example 1)-3 wasfurther confirmed by flow cytometry. Each HEK293T cell suspensionprepared in Example 1)-4-1 was centrifuged to remove supernatant. Then,the pcDNA3.1-DEST transfected HEK293T cells or the pcDNA3.1-hOrai1transfected HEK293T cells were suspended by the addition of thehybridoma culture supernatant and incubated at 4° C. for 1 hour. Thecells were washed once with PBS containing 5% FBS, then suspended by theaddition of Anti-Rat IgG FITC conjugate (Sigma-Aldrich Corp.) diluted500-fold with PBS containing 5% FBS, and left standing at 4° C. for 1hour. The cells were washed 3 times with PBS containing 5% FBS and thenresuspended in PBS containing 5% FBS and 2 μg/mL 7-aminoactinomycin D(Molecular Probes, Inc.), followed by detection using a flow cytometer(FC500; Beckman Coulter Inc.). The data was analyzed using Flowjo (TreeStar Inc.). After exclusion of 7-aminoactinomycin D positive dead cellsby gating, the FITC fluorescence intensity of live cells was plotted asa histogram. Hybridomas that yielded a sample exhibiting a shift tostronger fluorescence intensity in the histogram of the pcDNA3.1-hOrai1transfected HEK293T cells compared with the fluorescence intensityhistogram of the control pcDNA3.1-DEST transfected HEK293T cells wereobtained as hybridomas producing the anti-human Orai1 antibody. As aresult, 225 hybridomas exhibiting a significant shift were obtained.

1)-5 Isotyping of Antibody

The antibodies R118 and R198, which were suggested to bind to humanOrai1 strongly, were selected from among the rat anti-human Orai1antibodies produced by the hybridomas obtained in 1)-4, and isotyped.Their isotypes were determined using a Rat monoclonal isotyping test kit(AbD Serotec). As a result, the isotypes of the rat anti-human Orai1monoclonal antibodies R118 and R198 were both found to be IgG2a and κchains.

1)-6 Preparation of Rat Anti-Human Orai1 Antibody

Each rat anti-human Orai1 monoclonal antibody was purified from thehybridoma culture supernatant.

First, the hybridoma producing R118 or R198 was grown into a sufficientamount with ClonaCell-HY Selection Medium E. Then, the medium wasreplaced with Hybridoma SFM (Life Technologies Corp.) supplemented with20% of Ultra Low IgG FBS (Life Technologies Corp.), followed by culturefor 5 days. This culture supernatant was collected and sterilizedthrough a 0.45 μm filter.

The antibody was purified from the hybridoma supernatant by protein Gaffinity chromatography (at 4 to 6° C.) in one step. The bufferreplacement step after the purification by protein G affinitychromatography was carried out at 4 to 6° C. First, the hybridomaculture supernatant was applied to a column packed with protein G (GEHealthcare Bio-Sciences Corp.) equilibrated with PBS. After entry of thewhole culture supernatant in the column, the column was washed with PBSof 2 or more times the volume of the column. Next, fractions containingthe antibody were collected by elution with a 0.1 M aqueous glycinehydrochloride solution (pH 2.7). The collected fractions were preparedat pH 7.0 to 7.5 by the addition of 1 M Tris-HCl (pH 9.0) and thenbuffer replaced with PBS using Centrifugal UF Filter Device VIVASPIN 20(molecular weight cutoff: UF30K, Sartorius Japan K.K., 4 to 6° C.) whileconcentrated into an antibody concentration of 0.2 mg/mL or higher.Finally, the antibody solution was filtered through a Minisart-Plusfilter (Sartorius Japan K.K.) and used as a purified sample.

[Example 2] In Vitro Evaluation of Rat Anti-Human Orai1 Antibody

2)-1 Evaluation of Ability of Rat Anti-Human Orai1 Antibody to Bind byFlow Cytometry

In order to evaluate Orai1 binding specificity, the pcDNA3.1-DESTtransfected HEK293T cell suspension or the pcDNA3.1-hOrai1 transfectedHEK293T cell suspension prepared by the method shown in 1)-4-1 wascentrifuged to remove the supernatant. Then, the HEK293T cells weresuspended by the addition of the rat anti-human Orai1 monoclonalantibody R118 or R198 prepared in 1)-6 or a rat IgG control antibody(Beckman Coulter Inc.), and incubated at 4° C. for 30 minutes. The cellswere washed twice with PBS containing 5% FBS, then suspended by theaddition of Anti-Rat IgG FITC conjugate diluted 320-fold with PBScontaining 5% FBS, and incubated at 4° C. for 30 minutes. The cells werewashed twice with PBS containing 5% FBS and then resuspended in PBScontaining 5% FBS and 1 μg/mL propidium iodide (Life TechnologiesCorp.), followed by detection using a flow cytometer (FC500). The datawas analyzed using Flowjo. After exclusion of propidium iodide positivedead cells by gating, the FITC fluorescence intensity of live cells wasplotted as a histogram to calculate mean fluorescence intensity (MFI).R118 and R198 did not bind to the pcDNA3.1-DEST transfected HEK293Tcells and, as shown in FIG. 1, each bound only to the pcDNA3.1-hOrai1transfected HEK293T cells in a concentration dependent manner,demonstrating that these antibodies each specifically bind to humanOrai1. On the other hand, such binding was not observed in the rat IgGcontrol antibody.

2)-2 T Cell Activation Inhibitory Effect of Rat Anti-Human Orai1Antibody

Human T cell line Jurkat cells were prepared at a concentration of1.5×10⁶ cells/mL in RPMI1640 (Life Technologies Corp.) containing 10%FBS, 100 U/mL penicillin, and 100 μg/mL streptomycin (Life TechnologiesCorp.), inoculated at 80 μL/well to a 96-well cell culture plate, andpretreated with the rat anti-human Orai1 monoclonal antibody R118 orR198 or a rat IgG control antibody added at 10 μL/well at 37° C. for 60minutes under 5% CO₂ conditions. Then, 100 ng/mL PMA (Sigma-AldrichCorp.) and 1 μg/mL A23187 (Sigma-Aldrich Corp.) were added at 10 μL/well(final concentration: 10 ng/mL PMA and 100 ng/mL A23187) and wellstirred, followed by culture at 37° C. for approximately 16 hours under5% CO₂ conditions. The plate was well stirred and then centrifuged at600 g for 3 minutes. The interleukin-2 (IL-2) concentration contained inthe supernatant was measured by ELISA (R&D systems, Inc.). FIG. 2 showsthat the obtained rat anti-human Orai1 monoclonal antibodies eachinhibit, in a concentration dependent manner, the release of IL-2 fromJurkat cells treated with PMA and A23187. R118 and R198 each inhibitedthe IL-2 release from the Jurkat cells in a concentration dependentmanner. On the other hand, such inhibition was not observed in the ratIgG control antibody.

[Example 3] Determination of Nucleotide Sequences of cDNAs EncodingVariable Regions of Rat Anti-Human Orai1 Antibody

3)-1 cDNA Synthesis

A cell lysate (50 mM Tris-HCl (pH 7.5), 250 mM LiCl, 5 mM EDTA (pH 8),0.5% lithium dodecyl sulfate (LiDS), 2.5 mM dithiothreitol (DTT)) of thehybridoma producing each antibody R118 or R198 was mixed with magneticbeads (Dynabeads mRNA DIRECT Kit, Invitrogen Corp.) bound with oligodT25 so that mRNA bound to the magnetic beads. Next, the magnetic beadswere washed once each with mRNA washing solution A (10 mM Tris-HCl (pH7.5), 0.15 M LiCl, 1 mM EDTA, 0.1% LiDS, 0.1% Triton X-100) and asolution for cDNA synthesis (50 mM Tris-HCl (pH 8.3), 75 mM KCl, 3 mMMgCl₂, 5 mM DTT, 0.5 mM dNTP, 0.2% Triton X-100, 1.2 units of RNaseinhibitor (Life Technologies Corp.)), followed by cDNA synthesis using asolution for cDNA synthesis supplemented with 12 units of SuperScriptIII Reverse Transcriptase (Life Technologies Corp.). Subsequently, themagnetic beads were washed with a 3′ tailing reaction solution (50 mMpotassium phosphate, 4 mM MgCl₂, 0.5 mM dGTP, 0.2% Triton X-100, 1.2units of RNase inhibitor (Life Technologies Corp.)), followed by 3′tailing reaction using a reaction solution supplemented with 48 units ofTerminal Transferase, recombinant (F. Hoffmann-La Roche, Ltd.).

3)-2 Amplification and Sequencing of Rat Immunoglobulin Heavy and LightChain Variable Region Gene Fragments

The magnetic beads were washed with a TE solution (10 mM Tris-HCl (pH7.5), 1 mM EDTA, 0.1% Triton X-100), and then the rat immunoglobulinheavy and light chain genes were amplified by 5′-RACE PCR. Specifically,the magnetic beads were transferred to a PCR reaction solution (0.2 μMprimer, 0.2 mM dNTP, 0.25 units of PrimeSTAR HS DNA Polymerase (TakaraBio Inc.)) and subjected to 35 cycles of reaction each involving 94° C.for 30 seconds-68° C. for 90 seconds. The primer sets used were asfollows:

PCR Primer Set (for the Heavy Chain)

(Nhe-polyC-S) (SEQ ID NO: 3) 5′-GCTAGCGCTACCGGACTCAGATCCCCCCCCCCCCCDN-3′(rIgγ-AS1) (SEQ ID NO: 4) 5′-TCACTGAGCTGGTGAGAGTGTAGAGCCC-3′ (rIgγ-AS2)(SEQ ID NO: 5) 5′-TCACCGAGCTGCTGAGGGTGTAGAGCCC-3′PCR Primer Set (for the Light Chain)

(Nhe-polyC-S) (SEQ ID NO: 6) 5′-GCTAGCGCTACCGGACTCAGATCCCCCCCCCCCCCDN-3′(the same as that for the heavy chain) (rIgκ-AS) (SEQ ID NO: 7)5′-TCAGTAACACTGTCCAGGACACCATCTC-3′

The fragments amplified by the PCR reaction were sequenced to analyzetheir nucleotide sequences. An oligonucleotide having a nucleotidesequence of 5′-CTGGCTCAGGGAAATAGCC-3′ (rIgγ-seq) (SEQ ID NO: 8) was usedas a sequencing primer for the heavy chain, and an oligonucleotidehaving a nucleotide sequence of 5′-TCCAGTTGCTAACTGTTCC-3′ (rIgκ-seq)(SEQ ID NO: 9) was used as a sequencing primer for the light chain.

The sequencing analysis was carried out using a gene sequence analysisapparatus (“ABI PRISM 3700 DNA Analyzer; Applied Biosystems, Inc.” or“Applied Biosystems 3730xl Analyzer; Applied Biosystems, Inc.”). DyeTerminator Cycle Sequencing System with AmpliTaq DNA polymerase (LifeTechnologies Corp.) and GeneAmp 9700 (Applied Biosystems, Inc.) wereused in the sequencing reaction.

The determined nucleotide sequences encoding the heavy and light chainvariable regions of R118 and R198 are shown in SEQ ID NOs: 10 (R118light chain) and 12 (R118 heavy chain) and SEQ ID NOs: 14 (R198 lightchain) and 16 (R198 heavy chain), respectively, of the Sequence Listing.The amino acid sequences of the variable regions are shown in SEQ IDNOs: 11 (R118 light chain) and 13 (R118 heavy chain) and SEQ ID NOs: 15(R198 light chain) and 17 (R198 heavy chain), respectively, of theSequence Listing. SEQ ID NOs: 10 and 11 are shown in FIG. 14. SEQ IDNOs: 12 and 13 are shown in FIG. 15. SEQ ID NOs: 14 and 15 are shown inFIG. 16. SEQ ID NOs: 16 and 17 are shown in FIG. 17.

[Example 4] Preparation of Human Chimerized Anti-Human Orai1 Antibody

4)-1 Construction of Chimerized and Humanized Light Chain ExpressionVector pCMA-LK

A fragment of approximately 5.4 kb obtained by the digestion of aplasmid pcDNA3.3-TOPO/LacZ (Life Technologies Corp.) with restrictionenzymes XbaI and PmeI was ligated with a DNA fragment (shown in SEQ IDNO: 18 of the Sequence Listing) comprising a sequence encoding a human κchain secretion signal and a human κ chain constant region usingIn-Fusion Advantage PCR cloning kit (Clontech Laboratories, Inc.) toprepare pcDNA3.3/LK.

pcDNA3.3/LK was used as a template in PCR using the primer set givenbelow. The obtained fragment of approximately 3.8 kb was phosphorylatedand then self-ligated to construct a chimerized and humanized antibodylight chain expression vector pCMA-LK having a signal sequence, acloning site, and the human κ chain-constant region-encoding-sequencedownstream of a CMV promoter.

Primer Set

(SEQ ID NO: 19; primer 3.3-F1) 5′-TATACCGTCGACCTCTAGCTAGAGCTTGGC-3′(SEQ ID NO: 20; primer 3.3-R1) 5′-GCTATGGCAGGGCCTGCCGCCCCGACGTTG-3′

4)-2 Construction of Chimerized and Humanized IgG1 Type Heavy ChainExpression Vector pCMA-G1

A DNA fragment obtained by the digestion of pCMA-LK with XbaI and PmeIto remove the sequence encoding a κ chain secretion signal and a human κchain constant region was ligated with a DNA fragment (shown in SEQ IDNO: 21 of the Sequence Listing) comprising a sequence encoding a humanheavy chain signal sequence and amino acids of a human IgG1 constantregion using an In-Fusion Advantage PCR cloning kit to construct achimeric and humanized antibody IgG1 type heavy chain expression vectorpCMA-G1 having a signal sequence, a cloning site, and the human IgG1heavy chain constant-region-encoding-sequence downstream of a CMVpromoter.

4)-3 Construction of Human Chimerized Anti-Human Orai1 Antibody LightChain Expression Vector

4)-3-1 Construction of Human Chimerized R118 Light Chain cR118_LExpression Vector

A DNA fragment comprising the R118 light chainvariable-region-encoding-sequence obtained in Example 3)-2 wassynthesized (GeneArt Artificial Gene Synthesis service). A DNA fragmentof approximately 0.7 kb obtained by the cleavage of the DNA fragmentcomprising the R118 light chain variable-region-encoding-sequence withrestriction enzymes XbaI and PmeI was inserted into a DNA fragment ofapproximately 3.4 kb obtained by the cleavage of the general purposevector pCMA-LK for chimerized and humanized antibody light chainexpression with the same restriction enzymes as above using LigationHigh ver. 2 (Toyobo Co., Ltd.) to construct a human chimerized R118light chain (cR118_L) expression vector. The obtained expression vectorwas designated as “pCMA-LK/cR118_L”. The nucleotide sequence encodingthe human chimerized cR118 light chain and the amino acid sequence ofthe light chain are shown in SEQ ID NOs: 22 and 23 (FIG. 18),respectively, of the Sequence Listing.

4)-3-2 Construction of Human Chimerized R198 Light Chain cR198_LExpression Vector

A DNA fragment comprising the R198 light chainvariable-region-encoding-sequence obtained in Example 3)-2 wassynthesized (GeneArt Artificial Gene Synthesis service). A DNA fragmentof approximately 0.7 kb obtained by the cleavage of the DNA fragmentcomprising the R198 light chain variable-region-encoding-sequence withrestriction enzymes XbaI and PmeI was inserted into a DNA fragment ofapproximately 3.4 kb obtained by the cleavage of the general purposevector pCMA-LK for chimerized and humanized antibody light chainexpression with the same restriction enzymes as above using LigationHigh ver. 2 (Toyobo Co., Ltd.) to construct a human chimerized R198light chain (cR198_L) expression vector. The obtained expression vectorwas designated as “pCMA-LK/cR198_L”. The nucleotide sequence encodingthe human chimerized cR198 light chain and the amino acid sequence ofthe light chain are shown in SEQ ID NOs: 24 and 25 (FIG. 19),respectively, of the Sequence Listing.

4)-4 Construction of Human Chimerized Anti-Human Orai1 Antibody HeavyChain Expression Vector

4)-4-1 Construction of Human Chimerized R118 Heavy Chain cR118_HExpression Vector

A DNA fragment comprising the R118 heavy chainvariable-region-encoding-sequence obtained in Example 3)-2 wassynthesized (GeneArt Artificial Gene Synthesis service). A DNA fragmentof approximately 0.3 kb obtained by the cleavage of the DNA fragmentcomprising the R118 heavy chain variable-region-encoding-sequence with arestriction enzyme BlpI was inserted into a DNA fragment ofapproximately 4.5 kb obtained by the cleavage of the chimerized andhumanized IgG1 type heavy chain expression vector pCMA-G1 with the samerestriction enzyme as above using Ligation High ver. 2 to construct ahuman chimerized R118 heavy chain (cR118_H) expression vector. Theobtained expression vector was designated as “pCMA-G1/cR118_H”. Thenucleotide sequence encoding the human chimerized cR118 heavy chain andthe amino acid sequence of the heavy chain are shown in SEQ ID NOs: 26and 27 (FIG. 20), respectively, of the Sequence Listing.

4)-4-2 Construction of Human Chimerized R198 Heavy Chain cR198_HExpression Vector

A DNA fragment comprising the R198 heavy chainvariable-region-encoding-sequence obtained in Example 3)-2 wassynthesized (GeneArt Artificial Gene Synthesis service). A DNA fragmentof approximately 0.3 kb obtained by the cleavage of the DNA fragmentcomprising the R198 heavy chain variable-region-encoding-sequence with arestriction enzyme BlpI was inserted into a DNA fragment ofapproximately 4.5 kb obtained by the cleavage of the chimerized andhumanized IgG1 type heavy chain expression vector pCMA-G1 with the samerestriction enzyme as above using Ligation High ver. 2 to construct ahuman chimerized R198 heavy chain (cR198_H) expression vector. Theobtained expression vector was designated as “pCMA-G1/cR198_H”. Thenucleotide sequence encoding the human chimerized cR198 heavy chain andthe amino acid sequence of the heavy chain are shown in SEQ ID NOs: 28and 29 (FIG. 21), respectively, of the Sequence Listing.

4)-5 Preparation of Human Chimerized Anti-Human Orai1 Antibody

4)-5-1 Production of Human Chimerized Anti-Human Orai1 Antibody

FreeStyle 293F cells (Life Technologies Corp.) were subcultured andcultured according to the manual.

10⁷ FreeStyle 293F cells (Life Technologies Corp.) in the logarithmicgrowth phase were inoculated into a 30 mL bottle (Thermo FisherScientific Inc.), prepared at 9 mL by dilution with FreeStyle 293expression medium (Life Technologies Corp.), and then shake cultured at135 rpm at 37° C. for 1 hour in an 8% CO₂ incubator. 30 μg ofpolyethyleneimine (Polysciences #24765) was dissolved in 500 μL ofOpti-Pro SFM (Life Technologies Corp.). Next, each human chimerizedanti-human Orai1 antibody heavy chain expression vector (4 μg) and eachhuman chimerized anti-human Orai1 antibody light chain expression vector(6 μg), prepared using QIAGEN Plasmid Maxi Kit (Qiagen N.V.), weresuspended in 500 μL of Opti-Pro SFM. 500 μL of the expressionvector/Opti-Pro SFM mixed solution was added to 500 μL of thepolyethyleneimine/Opti-Pro SFM mixed solution, and the mixture wasgently stirred, further left for 5 minutes, and then added to theFreeStyle 293F cells. The cells were shake cultured at 95 rpm at 37° C.for 5 to 7 days in an 8% CO₂ incubator, and the obtained culturesupernatant was filtered through a 0.22 μm Millex Filter (MilliporeCorp.).

Human chimerized R118 obtained by the combination of pCMA-G1/cR118_H andpCMA-LK/cR118_L was designated as “cR118”. Likewise, human chimerizedR198 obtained by the combination of pCMA-G1/cR198_H and pCMA-LK/cR198_Lwas designated as “cR198”.

4)-5-2 Purification of Human Chimerized Anti-Human Orai1 Antibody

Each culture supernatant obtained in 4)-5-1 was purified by rProtein Aaffinity chromatography in one step. First, 10 mL of the culturesupernatant was applied to MabSelectSuRe (GE Healthcare Bio-SciencesCorp.) equilibrated with PBS. After entry of the whole culture solutionin the column, the column was washed with 7 mL of PBS. Next, elution wasperformed with 5 mL of 2 M arginine-HCl, pH 4.0, and the eluate wasbuffer replaced with 4 mL of a histidine buffer (25 mM histidine, 5%sorbitol, pH 6.0) using a PD-10 desalting column (GE HealthcareBio-Sciences Corp.). Finally, the solution was concentrated intoapproximately 100 μL using Amicon Ultracel 30K (molecular weight cutoff:30 K, Millipore Corp.) and used as a purified sample.

[Example 5] In Vitro Activity of Human Chimerized Anti-Human Orai1Antibody

5)-1 Antigen Binding Activity of Human Chimerized Anti-Human Orai1Antibody by Flow Cytometry

In order to evaluate human Orai1 binding specificity, the pcDNA3.1-DESTtransfected HEK293T cell suspension or the pcDNA3.1-hOrai1 transfectedHEK293T cell suspension prepared by the method shown in 1)-4-1 wascentrifuged to remove a supernatant. Then, the HEK293T cells weresuspended by the addition of the human chimerized anti-human Orai1antibody cR118 or cR198 prepared in 4)-5 or a human IgG control antibody(Jackson ImmunoResearch Laboratories, Inc.), and incubated at 4° C. for30 minutes. The cells were washed twice with PBS containing 5% FBS, thensuspended by the addition of Anti-human IgG FITC conjugate (JacksonImmunoResearch Laboratories, Inc.) diluted 100-fold with PBS containing5% FBS, and incubated at 4° C. for 30 minutes. The cells were washedtwice with PBS containing 5% FBS and then resuspended in PBS containing5% FBS and 1 μg/mL propidium iodide (Invitrogen Corp.), followed bydetection using a flow cytometer (FC500). The data was analyzed usingFlowjo. After exclusion of propidium iodide positive dead cells bygating, the FITC fluorescence intensity of live cells was plotted as ahistogram to calculate mean fluorescence intensity (MFI). cR118 andcR198 did not bind to the pcDNA3.1-DEST transfected HEK293T cells and,as shown in FIG. 3, each bound only to the pcDNA3.1-hOrai1 transfectedHEK293T cells in a concentration dependent manner, demonstrating thatthese antibodies each specifically bind to human Orai1. On the otherhand, such binding was not observed in the human IgG control antibody.

5)-2 Human T Cell Line Activation Inhibitory Effect of Human ChimerizedAnti-Human Orai1 Antibody

Human T cell line Jurkat cells were prepared at a concentration of1.5×10⁶ cells/mL in RPMI1640 containing 10% FBS, 100 U/mL penicillin,and 100 μg/mL streptomycin, inoculated at 80 μL/well onto a 96-well cellculture plate, and pretreated with the human chimerized anti-human Orai1antibody cR198 or cR118, the parent antibody R198, or a human IgGcontrol antibody added at 10 μL/well at 37° C. for 60 minutes under 5%CO₂ conditions. Then, 100 ng/mL PMA and 1 μg/mL A23187 were added at 10μL/well and well stirred, followed by culture at 37° C. forapproximately 16 hours under 5% CO₂ conditions. The plate was wellstirred and then centrifuged at 600 g for 3 minutes. The IL-2concentration contained in the supernatant was measured by ELISA. FIG. 4shows that the prepared human chimerized anti-human Orai1 antibodieseach inhibit, in a concentration dependent manner, the release of IL-2from Jurkat cells treated with PMA and A23187. cR118 and cR198 eachinhibited the IL-2 release from the Jurkat cells in a concentrationdependent manner with their inhibition strength equivalent to that ofthe parent antibody R198. On the other hand, such inhibition was notobserved in the human IgG control antibody.

[Example 6] Design of Humanized Version hR198 of Human ChimerizedAnti-Human Orai1 Antibody cR198

6)-1 Molecular Modeling of Variable Regions of R198

The molecular modeling of the variable regions of cR198 was carried outby a method generally known as homology modeling (Methods in Enzymology,203, 121-153, (1991)). The variable regions of R198 determined abovewere compared with the primary sequences (three-dimensional structuresderived from X-ray crystal structures are available) of humanimmunoglobulin variable regions registered in Protein Data Bank (Nuc.Acid Res. 28, 235-242 (2000)). As a result, 1AJ7 was selected as the onehaving the highest sequence homology to the light chain variable regionof cR198. Also, 1XGY was selected as the one having the highest sequencehomology to the heavy chain variable region of cR198. Thethree-dimensional structures of framework regions were prepared as a“framework model” by combining the coordinates of 1AJ7 and 1XGYcorresponding to the light chain and the heavy chain of cR198. The CDRsof cR198 were assigned as clusters 11A, 7A, 9A, 10A, and 10A to CDRL1,CDRL2, CDRL3, CDRH1, and CDRH2, respectively, according to theclassification of Thornton et al. (J. Mol. Biol., 263, 800-815, (1996)).Its CDRH3 was classified into k(6)—according to the H3 rule (FEBSletter, 399, 1-8 (1996)). Subsequently, the typical conformation of eachCDR was incorporated into the framework model.

Finally, an energy calculation for excluding disadvantageous interatomiccontact was conducted in order to obtain possible molecular models ofthe cR198 variable regions in terms of energy. These procedures wereperformed using a commercially available protein three-dimensionalstructure prediction program Prime and conformation search programMacroModel (Schrodinger, LLC).

6)-2 Design of Amino Acid Sequence of Humanized R198

The humanized R198 antibody was constructed by a method generally knownas CDR grafting (Proc. Natl. Acad. Sci. USA 86, 10029-10033 (1989)). Anacceptor antibody was selected on the basis of the homology of aminoacids in framework regions.

The sequences of the cR198 framework regions were compared with thesequences of all human frameworks registered in the Kabat database (Nuc.Acid Res., 29, 205-206 (2001)) of antibody amino acid sequences. As aresult, a 1C10′CL antibody was selected as an acceptor due to its 71%sequence homology as to framework regions. The amino acid residues offramework regions in 1C10′CL were aligned with the amino acid residuesof the cR198 framework regions to identify the positions of amino acidsthat did not match therebetween. The positions of these residues wereanalyzed using the three-dimensional model of cR198 constructed above.Then, the donor residues to be grafted onto the acceptor were selectedaccording to the criteria provided by Queen et al. (Proc. Natl. Acad.Sci. USA 86, 10029-10033 (1989)).

Some donor residues thus selected were transferred to the acceptorantibody to construct the humanized R198 sequence as described in theExamples below.

In addition, 1 to 5 amino acid residues in each CDR or FR of cR198 werereplaced with amino acid residues of cR118 to construct a CDR engineeredhumanized R198 sequence as described in the Examples below.

6)-3 Design of Humanized R198 Light Chain hR198_L 6)-3-1 hR198_L1 TypeLight Chain:

A humanized R198 light chain designed by replacing a threonine residueat amino acid position 30 with a serine residue, a proline residue atamino acid position 32 with a serine residue, a leucine residue at aminoacid position 35 with a valine residue, a glutamic acid residue at aminoacid position 37 with an aspartic acid residue, a serine residue atamino acid position 42 with a threonine residue, an aspartic acidresidue at amino acid position 61 with a glycine residue, a glycineresidue at amino acid position 62 with a lysine residue, a serineresidue at amino acid position 63 with an alanine residue, a valineresidue at amino acid position 64 with a proline residue, a serineresidue at amino acid position 92 with a threonine residue, a serineresidue at amino acid position 94 with a threonine residue, a threonineresidue at amino acid position 96 with a serine residue, a glutamic acidresidue at amino acid position 99 with a glutamine residue, a serineresidue at amino acid position 100 with a proline residue, a threonineresidue at amino acid position 120 with a glutamine residue, a leucineresidue at amino acid position 124 with a valine residue, a leucineresidue at amino acid position 126 with an isoleucine residue, anarginine residue at amino acid position 127 with a lysine residue, andan alanine residue at amino acid position 129 with a threonine residueas to the cR198 light chain shown in SEQ ID NO: 25 of the SequenceListing was designated as a “hR198_L1 type light chain”.

The nucleotide sequence encoding the hR198_L1 type light chain is shownin SEQ ID NO: 30 of the Sequence Listing. Nucleotide positions 61 to 702encode a mature light chain formed by the cleavage of the signalsequence. Nucleotide positions 61 to 378 encode the variable region. Theamino acid sequence of the hR198_L1 type light chain is shown in SEQ IDNO: 31 of the Sequence Listing. Amino acid positions 21 to 234 representthe mature light chain formed by the cleavage of the signal sequence.Amino acid positions 21 to 126 represent the variable region. Both ofthe sequences of SEQ ID NOs: 30 and 31 are also shown in FIG. 22. EachCDR sequence and its corresponding SEQ ID NO are shown in FIG. 38.

6)-3-2 hR198_L2 Type Light Chain:

A humanized R198 light chain designed by replacing a threonine residueat amino acid position 30 with a serine residue, a proline residue atamino acid position 32 with a serine residue, a leucine residue at aminoacid position 35 with a valine residue, a glutamic acid residue at aminoacid position 37 with an aspartic acid residue, a serine residue atamino acid position 42 with a threonine residue, an aspartic acidresidue at amino acid position 61 with a glycine residue, a glycineresidue at amino acid position 62 with a lysine residue, a serineresidue at amino acid position 63 with an alanine residue, a serineresidue at amino acid position 92 with a threonine residue, a serineresidue at amino acid position 94 with a threonine residue, a threonineresidue at amino acid position 96 with a serine residue, a glutamic acidresidue at amino acid position 99 with a glutamine residue, a serineresidue at amino acid position 100 with a proline residue, a threonineresidue at amino acid position 120 with a glutamine residue, a leucineresidue at amino acid position 124 with a valine residue, a leucineresidue at amino acid position 126 with an isoleucine residue, anarginine residue at amino acid position 127 with a lysine residue, andan alanine residue at amino acid position 129 with a threonine residueas to the cR198 light chain shown in SEQ ID NO: 25 of the SequenceListing was designated as a “hR198_L2 type light chain”.

The nucleotide sequence encoding the hR198_L2 type light chain is shownin SEQ ID NO: 32 of the Sequence Listing. Nucleotide positions 61 to 702encode a mature light chain formed by the cleavage of the signalsequence. Nucleotide positions 61 to 378 encode the variable region. Theamino acid sequence of the hR198_L2 type light chain is shown in SEQ IDNO: 33 of the Sequence Listing. Amino acid positions 21 to 234 representthe mature light chain formed by the cleavage of the signal sequence.Amino acid positions 21 to 126 represent the variable region. Both ofthe sequences of SEQ ID NOs: 32 and 33 are also shown in FIG. 23. EachCDR sequence and its corresponding SEQ ID NO are shown in FIG. 38.

6)-3-3 hR198_L3 Type Light Chain:

A humanized R198 light chain designed by replacing a threonine residueat amino acid position 30 with a serine residue, a proline residue atamino acid position 32 with a serine residue, a leucine residue at aminoacid position 35 with a valine residue, a glutamic acid residue at aminoacid position 37 with an aspartic acid residue, a serine residue atamino acid position 42 with a threonine residue, an aspartic acidresidue at amino acid position 61 with a glycine residue, a glycineresidue at amino acid position 62 with a lysine residue, a serineresidue at amino acid position 63 with an alanine residue, a valineresidue at amino acid position 64 with a proline residue, a serineresidue at amino acid position 92 with a threonine residue, a serineresidue at amino acid position 94 with a threonine residue, a threonineresidue at amino acid position 96 with a serine residue, a glutamic acidresidue at amino acid position 99 with a glutamine residue, a serineresidue at amino acid position 100 with a proline residue, a tyrosineresidue at amino acid position 114 with a phenylalanine residue, athreonine residue at amino acid position 120 with a glutamine residue, aleucine residue at amino acid position 124 with a valine residue, aleucine residue at amino acid position 126 with an isoleucine residue,an arginine residue at amino acid position 127 with a lysine residue,and an alanine residue at amino acid position 129 with a threonineresidue as to the cR198 light chain shown in SEQ ID NO: 25 of theSequence Listing was designated as a “hR198_L3 type light chain”.

The nucleotide sequence encoding the hR198_L3 type light chain is shownin SEQ ID NO: 34 of the Sequence Listing. Nucleotide positions 61 to 702encode a mature light chain formed by the cleavage of the signalsequence. Nucleotide positions 61 to 378 encode the variable region. Theamino acid sequence of the hR198_L3 type light chain is shown in SEQ IDNO: 35 of the Sequence Listing. Amino acid positions 21 to 234 representthe mature light chain formed by the cleavage of the signal sequence.Amino acid positions 21 to 126 represent the variable region. Both ofthe sequences of SEQ ID NOs: 34 and 35 are also shown in FIG. 24. EachCDR sequence and its corresponding SEQ ID NO are shown in FIG. 38.

6)-3-4 hR198_L4 Type Light Chain:

A humanized R198 light chain designed by replacing a threonine residueat amino acid position 30 with a serine residue, a proline residue atamino acid position 32 with a serine residue, a leucine residue at aminoacid position 35 with a valine residue, a glutamic acid residue at aminoacid position 37 with an aspartic acid residue, a serine residue atamino acid position 42 with a threonine residue, an aspartic acidresidue at amino acid position 61 with a glycine residue, a glycineresidue at amino acid position 62 with a lysine residue, a serineresidue at amino acid position 63 with an alanine residue, a serineresidue at amino acid position 92 with a threonine residue, a serineresidue at amino acid position 94 with a threonine residue, a threonineresidue at amino acid position 96 with a serine residue, a glutamic acidresidue at amino acid position 99 with a glutamine residue, a serineresidue at amino acid position 100 with a proline residue, a tyrosineresidue at amino acid position 114 with a phenylalanine residue, athreonine residue at amino acid position 120 with a glutamine residue, aleucine residue at amino acid position 124 with a valine residue, aleucine residue at amino acid position 126 with an isoleucine residue,an arginine residue at amino acid position 127 with a lysine residue,and an alanine residue at amino acid position 129 with a threonineresidue as to the cR198 light chain shown in SEQ ID NO: 25 of theSequence Listing was designated as a “hR198_L4 type light chain”.

The nucleotide sequence encoding the hR198_L4 type light chain is shownin SEQ ID NO: 36 of the Sequence Listing. Nucleotide positions 61 to 702encode a mature light chain formed by the cleavage of the signalsequence. Nucleotide positions 61 to 378 encode the variable region. Theamino acid sequence of the hR198_L4 type light chain is shown in SEQ IDNO: 37 of the Sequence Listing. Amino acid positions 21 to 234 representthe mature light chain formed by the cleavage of the signal sequence.Amino acid positions 21 to 126 represent the variable region. Both ofthe sequences of SEQ ID NOs: 36 and 37 are also shown in FIG. 25. EachCDR sequence and its corresponding SEQ ID NO are shown in FIG. 38.

6)-4 Design of Humanized R198 Heavy Chain hR198_H

6)-4-1 hR198_H1 Type Heavy Chain:

A humanized R198 heavy chain designed by replacing a glutamine residueat amino acid position 24 with a valine residue, a leucine residue atamino acid position 30 with a valine residue, an alanine residue atamino acid position 31 with a lysine residue, a serine residue at aminoacid position 35 with an alanine residue, a methionine residue at aminoacid position 37 with a valine residue, an isoleucine residue at aminoacid position 39 with a valine residue, an isoleucine residue at aminoacid position 56 with a valine residue, a lysine residue at amino acidposition 57 with an arginine residue, a threonine residue at amino acidposition 59 with an alanine residue, a threonine residue at amino acidposition 60 with a proline residue, a lysine residue at amino acidposition 86 with an arginine residue, a serine residue at amino acidposition 95 with a threonine residue, a phenylalanine residue at aminoacid position 99 with a tyrosine residue, a glutamine residue at aminoacid position 101 with a glutamic acid residue, a threonine residue atamino acid position 106 with an arginine residue, a proline residue atamino acid position 107 with a serine residue, an aspartic acid residueat amino acid position 108 with a glutamic acid residue, a serineresidue at amino acid position 110 with a threonine residue, a valineresidue at amino acid position 130 with a threonine residue, and amethionine residue at amino acid position 131 with a leucine residue asto the cR198 heavy chain shown in SEQ ID NO: 29 of the Sequence Listingwas designated as a “hR198_H1 type heavy chain”.

The nucleotide sequence encoding the hR198_H1 type heavy chain is shownin SEQ ID NO: 38 of the Sequence Listing. Nucleotide positions 58 to1398 encode a mature heavy chain formed by the cleavage of the signalsequence. Nucleotide positions 58 to 408 encode the variable region. Theamino acid sequence of the hR198_H1 type heavy chain is shown in SEQ IDNO: 39 of the Sequence Listing. Amino acid positions 20 to 466 representthe mature heavy chain formed by the cleavage of the signal sequence.Amino acid positions 20 to 136 represent the variable region. Both ofthe sequences of SEQ ID NOs: 38 and 39 are also shown in FIG. 26. EachCDR sequence and its corresponding SEQ ID NO are shown in FIG. 38.

6)-4-2 hR198_H2 Type Heavy Chain:

A humanized R198 heavy chain designed by replacing a glutamine residueat amino acid position 24 with a valine residue, a leucine residue atamino acid position 30 with a valine residue, an alanine residue atamino acid position 31 with a lysine residue, a serine residue at aminoacid position 35 with an alanine residue, a methionine residue at aminoacid position 37 with a valine residue, an isoleucine residue at aminoacid position 39 with a valine residue, a lysine residue at amino acidposition 57 with an arginine residue, a threonine residue at amino acidposition 59 with an alanine residue, a threonine residue at amino acidposition 60 with a proline residue, a lysine residue at amino acidposition 86 with an arginine residue, a serine residue at amino acidposition 95 with a threonine residue, a phenylalanine residue at aminoacid position 99 with a tyrosine residue, a glutamine residue at aminoacid position 101 with a glutamic acid residue, a threonine residue atamino acid position 106 with an arginine residue, a proline residue atamino acid position 107 with a serine residue, an aspartic acid residueat amino acid position 108 with a glutamic acid residue, a serineresidue at amino acid position 110 with a threonine residue, a valineresidue at amino acid position 130 with a threonine residue, and amethionine residue at amino acid position 131 with a leucine residue asto the cR198 heavy chain shown in SEQ ID NO: 29 of the Sequence Listingwas designated as a “hR198_H2 type heavy chain”.

The nucleotide sequence encoding the hR198_H2 type heavy chain is shownin SEQ ID NO: 40 of the Sequence Listing. Nucleotide positions 58 to1398 encode a mature heavy chain formed by the cleavage of the signalsequence. Nucleotide positions 58 to 408 encode the variable region. Theamino acid sequence of the hR198_H2 type heavy chain is shown in SEQ IDNO: 41 of the Sequence Listing. Amino acid positions 20 to 466 representthe mature heavy chain formed by the cleavage of the signal sequence.Amino acid positions 20 to 136 represent the variable region. Both ofthe sequences of SEQ ID NOs: 40 and 41 are also shown in FIG. 27. EachCDR sequence and its corresponding SEQ ID NO are shown in FIG. 38.

6)-4-3 hR198_H3 Type Heavy Chain:

A humanized R198 heavy chain designed by replacing a glutamine residueat amino acid position 24 with a valine residue, a leucine residue atamino acid position 30 with a valine residue, an alanine residue atamino acid position 31 with a lysine residue, a serine residue at aminoacid position 35 with an alanine residue, a methionine residue at aminoacid position 37 with a valine residue, an isoleucine residue at aminoacid position 39 with a valine residue, a serine residue at amino acidposition 50 with an alanine residue, an isoleucine residue at amino acidposition 56 with a valine residue, a lysine residue at amino acidposition 57 with an arginine residue, a threonine residue at amino acidposition 59 with an alanine residue, a threonine residue at amino acidposition 60 with a proline residue, an isoleucine residue at amino acidposition 67 with a valine residue, a valine residue at amino acidposition 70 with an isoleucine residue, a glutamic acid residue at aminoacid position 81 with an alanine residue, a lysine residue at amino acidposition 82 with an arginine residue, a lysine residue at amino acidposition 86 with an arginine residue, a serine residue at amino acidposition 95 with a threonine residue, a phenylalanine residue at aminoacid position 99 with a tyrosine residue, a glutamine residue at aminoacid position 101 with a glutamic acid residue, a threonine residue atamino acid position 106 with an arginine residue, a proline residue atamino acid position 107 with a serine residue, an aspartic acid residueat amino acid position 108 with a glutamic acid residue, a serineresidue at amino acid position 110 with a threonine residue, a valineresidue at amino acid position 130 with a threonine residue, and amethionine residue at amino acid position 131 with a leucine residue asto the cR198 heavy chain shown in SEQ ID NO: 29 of the Sequence Listingwas designated as a “hR198_H3 type heavy chain”.

The nucleotide sequence encoding the hR198_H3 type heavy chain is shownin SEQ ID NO: 42 of the Sequence Listing. Nucleotide positions 58 to1398 encode a mature heavy chain formed by the cleavage of the signalsequence. Nucleotide positions 58 to 408 encode the variable region. Theamino acid sequence of the hR198_H3 type heavy chain is shown in SEQ IDNO: 43 of the Sequence Listing. Amino acid positions 20 to 466 representthe mature heavy chain formed by the cleavage of the signal sequence.Amino acid positions 20 to 136 represent the variable region. Both ofthe sequences of SEQ ID NOs: 42 and 43 are also shown in FIG. 28. EachCDR sequence and its corresponding SEQ ID NO are shown in FIG. 38.

6)-4-4 hR198_H4 Type Heavy Chain:

A humanized R198 heavy chain designed by replacing a glutamine residueat amino acid position 24 with a valine residue, a leucine residue atamino acid position 30 with a valine residue, an alanine residue atamino acid position 31 with a lysine residue, a serine residue at aminoacid position 35 with an alanine residue, a methionine residue at aminoacid position 37 with a valine residue, an isoleucine residue at aminoacid position 39 with a valine residue, a serine residue at amino acidposition 50 with an alanine residue, a lysine residue at amino acidposition 57 with an arginine residue, a threonine residue at amino acidposition 59 with an alanine residue, a threonine residue at amino acidposition 60 with a proline residue, an isoleucine residue at amino acidposition 67 with a valine residue, a valine residue at amino acidposition 70 with an isoleucine residue, a glutamic acid residue at aminoacid position 81 with an alanine residue, a lysine residue at amino acidposition 82 with an arginine residue, a lysine residue at amino acidposition 86 with an arginine residue, a serine residue at amino acidposition 95 with a threonine residue, a phenylalanine residue at aminoacid position 99 with a tyrosine residue, a glutamine residue at aminoacid position 101 with a glutamic acid residue, a threonine residue atamino acid position 106 with an arginine residue, a proline residue atamino acid position 107 with a serine residue, an aspartic acid residueat amino acid position 108 with a glutamic acid residue, a serineresidue at amino acid position 110 with a threonine residue, a valineresidue at amino acid position 130 with a threonine residue, and amethionine residue at amino acid position 131 with a leucine residue asto the cR198 heavy chain shown in SEQ ID NO: 29 of the Sequence Listingwas designated as a “hR198_H4 type heavy chain”.

The nucleotide sequence encoding the hR198_H4 type heavy chain is shownin SEQ ID NO: 44 of the Sequence Listing. Nucleotide positions 58 to1398 encode a mature heavy chain formed by the cleavage of the signalsequence. Nucleotide positions 58 to 408 encode the variable region. Theamino acid sequence of the hR198_H4 type heavy chain is shown in SEQ IDNO: 45 of the Sequence Listing. Amino acid positions 20 to 466 representthe mature heavy chain formed by the cleavage of the signal sequence.Amino acid positions 20 to 136 represent the variable region. Both ofthe sequences of SEQ ID NOs: 44 and 45 are also shown in FIG. 29. EachCDR sequence and its corresponding SEQ ID NO are shown in FIG. 38.

[Example 7] Preparation of Humanized Anti-Human Orai1 Antibody

7)-1 Construction of Humanized Anti-Human Orai1 Antibody Light ChainhR198_L Expression Vector

7)-1-1 Construction of hR198_L1 Expression Vector

A DNA fragment comprising the hR198_L1 variable-region-encoding-sequenceshown in nucleotide positions 38 to 402 in the nucleotide sequence ofhR198_L1 represented by SEQ ID NO: 30 of the Sequence Listing wassynthesized (GeneArt Artificial Gene Synthesis service). The synthesizedDNA fragment was cleaved with restriction enzymes AvaI and EcoRV andinserted into the corresponding site of the chimeric and humanizedantibody light chain expression vector pCMA-LK cleaved with the samerestriction enzymes as above to construct a hR198_L1 expression vector.The obtained expression vector was designated as “pCMA-LK/hR198_L1”.

7)-1-2 Construction of hR198_L2 Expression Vector

A DNA fragment comprising the hR198_L2 variable-region-encoding-sequenceshown in nucleotide positions 38 to 402 in the nucleotide sequence ofhR198_L2 represented by SEQ ID NO: 32 of the Sequence Listing wassynthesized (GeneArt Artificial Gene Synthesis service). The DNAfragment comprising the hR198_L2 variable-region-encoding-sequence wasamplified with the synthesized DNA fragment as a template using KOD-Plus- (Toyobo Co., Ltd.), cleaved with restriction enzyme BsiWI, andinserted into the corresponding site of the chimeric and humanizedantibody light chain expression vector pCMA-LK cleaved with therestriction enzyme BsiWI to construct a hR198_L2 expression vector. Theobtained expression vector was designated as “pCMA-LK/hR198_L2”.

7)-1-3 Construction of hR198_L3 and hR198_L4 Expression Vectors

A DNA fragment comprising the hR198_L4 variable-region-encoding-sequenceshown in nucleotide positions 38 to 402 in the nucleotide sequence ofhR198_L4 represented by SEQ ID NO: 36 of the Sequence Listing wassynthesized (GeneArt Artificial Gene Synthesis service). A hR198_L4expression vector was constructed by the same method as in Example7)-1-2. The obtained expression vector was designated as“pCMA-LK/hR198_L4”.

A mutation to replace the valine residue at amino acid position 64 witha proline residue was introduced with pCMA-LK/hR198_L4 as the templateusing a QuikChange Site-Directed Mutagenesis Kit (Stratagene Corp.). Theobtained expression vector comprising the nucleotide sequencerepresented by SEQ ID NO: 34 of the Sequence Listing was designated as“pCMA-LK/hR198_L3”.

7)-2 Construction of Humanized Anti-Human Orai1 Antibody Heavy ChainhR198_H Expression Vector 7)-2-1 Construction of hR198_H1 and hR198_H2Expression Vectors

A DNA fragment comprising the hR198_H0 variable region encoding thesequence shown in nucleotide positions 36 to 425 in the nucleotidesequence of hR198_H0 represented by SEQ ID NO: 111 of the SequenceListing was synthesized as a candidate for the humanization of theanti-Orai1 antibody heavy chain hR198 (GeneArt Artificial Gene Synthesisservice). The DNA fragment comprising the hR198_H0variable-region-encoding-sequence was amplified with the synthesized DNAfragment as a template using KOD -Plus- and inserted into thecorresponding site of the chimeric and humanized antibody IgG1 typeheavy chain expression vector pCMA-G1 cleaved with restriction enzymeBlpI using an In-Fusion HD PCR cloning kit (Clontech Laboratories, Inc.)to construct a hR198_H0 expression vector. The obtained expressionvector was designated as “pCMA-G1/hR198_H0”. The amino acid sequence ofhR198_H0 is shown in SEQ ID NO: 112.

Next, a mutation to replace a tryptophan residue at amino acid position66 with a tyrosine residue was introduced with pCMA-G1/hR198_H0 as thetemplate using a KOD -Plus- mutagenesis kit (Toyobo Co., Ltd.). Theobtained expression vector comprising the nucleotide sequencerepresented by SEQ ID NO: 40 of the Sequence Listing was designated as“pCMA-G1/hR198_H2”.

Next, a mutation to replace an isoleucine residue at amino acid position56 with a valine residue was introduced with pCMA-G1/hR198_H2 as thetemplate using a QuikChange Site-Directed Mutagenesis Kit (StratageneCorp.) and the primer set given below. The obtained expression vectorcomprising the nucleotide sequence represented by SEQ ID NO: 38 of theSequence Listing was designated as “pCMA-G1/hR198_H1”.

7)-2-2 Construction of hR198_H3, hR198_H4 and hR198_H5 ExpressionVectors

A DNA fragment comprising the hR198_H5 variable region encoding thesequence shown in nucleotide positions 36 to 425 in the nucleotidesequence of hR198_H5 represented by SEQ ID NO: 113 of the SequenceListing was synthesized as a candidate for the humanization of theanti-Orai1 antibody heavy chain hR198 (GeneArt Artificial Gene Synthesisservice). A hR198_H5 expression vector was constructed by the samemethod as in Example 7)-2-1. The obtained expression vector wasdesignated as “pCMA-G1/hR198_H5”. The amino acid sequence of hR198_H5 isshown in SEQ ID NO: 114.

Next, mutations to replace a tryptophan residue at amino acid position66 and an isoleucine residue at amino acid position 67 with a tyrosineresidue and a valine residue, respectively, were introduced withpCMA-G1/H5 as the template using a KOD -Plus- mutagenesis kit. Theobtained expression vector comprising the nucleotide sequencerepresented by SEQ ID NO: 44 was designated as “pCMA-G1/hR198_H4”.

Next, a mutation to replace an isoleucine residue at amino acid position56 with a valine residue was introduced by the same method as in Example7)-2-1 with pCMA-G1/hR198_H4 as a template. The obtained expressionvector comprising the nucleotide sequence represented by SEQ ID NO: 44of the Sequence Listing was designated as “pCMA-G1/hR198_H3”.

7)-3 Preparation of Humanized Anti-Human Orai1 Antibody hR198

FreeStyle 293F cells were transfected with each humanized anti-humanOrai1 antibody heavy chain expression vector and each humanizedanti-human Orai1 antibody light chain expression vector by the samemethod as in 4)-5-1 to obtain a culture supernatant containing theantibody.

Humanized anti-human Orai1 antibodies obtained by the combination ofpCMA-G1/hR198_H1 and pCMA-LK/hR198_L1, the combination ofpCMA-G1/hR198_H2 and pCMA-LK/hR198_L2, the combination ofpCMA-G1/hR198_H3 and pCMA-LK/hR198_L3, and the combination ofpCMA-G1/hR198_H4 and pCMA-LK/hR198_L4 were designated as “hR198_H1/L1”,“hR198_H2/L2”, “hR198_H3/L3”, and “hR198_H4/L4”, respectively.

Each obtained culture supernatant was purified by rProtein A affinitychromatography by the same method as in 4)-5-2 to obtain a purifiedantibody sample.

[Example 8] In Vitro Activity of Humanized Anti-Human Orai1 Antibody

8)-1 Antigen Binding Activity of Humanized Anti-Human Orai1 Antibody byFlow Cytometry

In order to evaluate human Orai1 binding specificity, the pcDNA3.1-DESTtransfected HEK293T cell suspension or the pcDNA3.1-hOrai1 transfectedHEK293T cell suspension prepared by the method shown in 1)-4-1 wascentrifuged to remove supernatant. Then, the HEK293T cells weresuspended by the addition of the humanized anti-Orai1 antibodyhR198_H1/L1, hR198_H2/L2, hR198_H3/L3, or hR198_H4/L4 prepared in 7)-5or the parent antibody cR118 or cR198, and incubated at 4° C. for 30minutes. The cells were washed twice with PBS containing 5% FBS, thensuspended by the addition of Anti-human IgG FITC conjugate diluted100-fold with PBS containing 5% FBS, and incubated at 4° C. for 30minutes. The cells were washed twice with PBS containing 5% FBS and thenresuspended in PBS containing 5% FBS and 1 μg/mL propidium iodide,followed by detection using a flow cytometer (FC500). The data wasanalyzed using Flowjo. After exclusion of propidium iodide positive deadcells by gating, the FITC fluorescence intensity of live cells wasplotted as a histogram to calculate mean fluorescence intensity (MFI).The humanized anti-human Orai1 antibodies hR198_H1/L1, hR198_H2/L2,hR198_H3/L3, and hR198_H4/L4 did not bind to the pcDNA3.1-DESTtransfected HEK293T cells and, as shown in FIG. 5, each bound only tothe pcDNA3.1-hOrai1 transfected HEK293T cells in a concentrationdependent manner, as with the parent antibody cR118 or cR198,demonstrating that these antibodies each specifically bind to humanOrai1.

8)-2 Human T cell line activation inhibitory effect of humanizedanti-human Orai1 antibody

Human T cell line Jurkat cells were prepared at a concentration of1.5×10⁶ cells/mL in RPMI1640 containing 10% FBS, 100 U/mL penicillin,and 100 μg/mL streptomycin, inoculated at 80 μL/well to a 96-well cellculture plate, and pretreated with the humanized anti-human Orai1antibody hR198_H1/L1, hR198_H2/L2, hR198_H3/L3, or hR198_H4/L4 or thehuman chimerized anti-human Orai1 antibody cR118 or cR198 added at 10μL/well at 37° C. for 60 minutes under 5% CO₂ conditions. Then, 100ng/mL PMA and 1 μg/mL A23187 were added at 10 μL/well and well stirred,followed by culture at 37° C. for approximately 16 hours under 5% CO₂conditions. The plate was well stirred and then centrifuged at 600 g for3 minutes. The IL-2 concentration contained in the supernatant wasmeasured by ELISA. FIG. 6 shows that the humanized anti-human Orai1antibodies each inhibit, in a concentration dependent manner, therelease of IL-2 from Jurkat cells treated with PMA and A23187. Thehumanized anti-human Orai1 antibodies each inhibited the IL-2 releasefrom the Jurkat cells in a concentration dependent manner, and theinhibitory activity of hR198_H1/L1 and hR198_H2/L2 was equivalent tothat of the human chimerized anti-human Orai1 antibodies cR118 andcR198. On the other hand, hR198_H3/L3 and hR198_H4/L4 exhibitedinhibitory activity at a lower concentration than that of cR118 andcR198.

[Example 9] Identification of Activity Enhancing Mutation by RibosomeDisplay

9)-1 Preparation of H Chain and L Chain Libraries

A library containing mutated H chains or L chains was constructed withthe humanized anti-human Orai1 antibody hR198_H4/L4 as a template andsubjected to the identification of an activity enhancing mutation byribosome display.

9)-1-1 Preparation of H Chain Library

80 cycles of PCR were carried out with the hR198_H4 gene as a templateusing the primer set given below and rTaq DNA polymerase (Toyobo Co.,Ltd.) to mutate the gene region randomly.

Primer Set

(SEQ ID NO: 46; primer Orail HF) 5′-ATGCAAGTCCAACTGGTTCAATC-3′(SEQ ID NO: 47; primer Orail CH FR) 5′-TGACGGAGCCAGCGGGAAGAC-3′

Next, overlap PCR was carried out with each randomly mutated H chaingene, a 5′UTR site comprising a T7 promoter, and a TolA gene fragmentcomprising 5′ added c-Myc and a 3′ added SecM sequence as templatesusing the primer set given below to prepare an H chain library.

Primer Set

(SEQ ID NO: 48; primer M13 rev long) 5′-CAGGAAACAGCTATGACCATG-3′(SEQ ID NO: 49; primer SecM Stop R)5′-CTCGAGTTATTCATTAGGTGAGGCGTTGAGG-3′

9)-1-2 Preparation of L Chain Library

80 cycles of PCR were carried out with the hR198_L4 gene as a templateusing the primer set given below and rTaq DNA polymerase to mutate thegene region randomly.

Primer Set

(SEQ ID NO: 50; primer Orail Lc F) 5′-ATGGACATTCAACTGACCCAAAGC-3′(SEQ ID NO: 51; primer Orail CL-FR) 5′-GATAAAAACACTCGGGGCCGCCAC-3′

In the same way as in the description of 9)-1-1, overlap PCR was carriedout using each randomly mutated L chain gene and the two gene fragmentsdescribed above as templates to prepare an L chain library.

9)-1-3 Preparation of H Chain Gene Fragment

The H chain gene region was amplified by PCR with the hR198_H4 gene as atemplate using the primer set given below and KOD -Plus-.

Primer Set

(SEQ ID NO: 46; primer Orail HF) 5′-ATGCAAGTCCAACTGGTTCAATC-3′(SEQ ID NO: 52; primer Orail HR-FLAG R)5′-TCATTATTTGTCATCGTCATCTTTATAGTCGAATTCTTCGCCACG ATTAAAGGATTTGGTGAC-3′

Next, overlap PCR was carried out with the gene fragment and a 5′UTRsite comprising a T7 promoter as templates using the primer set givenbelow to prepare an H chain gene fragment.

Primer Set

(SEQ ID NO: 48; primer M13 rev long) 5′-CAGGAAACAGCTATGACCATG-3′(SEQ ID NO: 52; primer Orail HR-FLAG R)5′-TCATTATTTGTCATCGTCATCTTTATAGTCGAATTCTTCGCCACGAT TAAAGGATTTGGTGAC-3′

9)-1-4 Preparation of L Chain Gene Fragment

The L chain gene region was amplified by PCR with the hR198_L4 gene as atemplate using the primer set given below and KOD -Plus-.

Primer Set

(SEQ ID NO: 50; primer Orail Lc F) 5′-ATGGACATTCAACTGACCCAAAGC-3′(SEQ ID NO: 53; primer Orail CL-FLAG R)5′-TCATTATTTGTCATCGTCATCTTTATAGTCGAATTCTTCGCCACGA TTAAAGGATTTGGTGAC-3′

Next, in the same way as in the description of 9)-1-3 overlap PCR wascarried out to prepare an L chain gene fragment.

Primer Set

(SEQ ID NO: 48; primer M13 rev long) 5′-CAGGAAACAGCTATGACCATG-3′(SEQ ID NO: 53; primer Orail CL-FLAG R)5′-TCATTATTTGTCATCGTCATCTTTATAGTCGAATTCTTCGCCACGA TTAAAGGATTTGGTGAC-3′

9)-1-5 Preparation of mRNA

Each mRNA was synthesized with the libraries and the gene fragmentsprepared in Examples 9)-1-1 to 9)-1-4 as templates using the T7 RiboMaxExpress Large Scale RNA Production System (Promega Corp.).

9)-2 Screening by Ribosome Display

H chain ribosome display Fabs were prepared by the combination of the Hchain library and the L chain gene fragment, and L chain ribosomedisplay Fabs were prepared by the combination of the L chain library andthe H chain gene fragment. 20 pmol of the H chain (or L chain) librarymRNAs and 100 pmol of ribosomes were added to a PUREfrex reactionsolution (GeneFrontier Corp.), and the mixture was incubated at 30° C.for 45 minutes. Likewise, 40 pmol of the L chain (or H chain) mRNAs and200 pmol of ribosomes were added to a PUREfrex reaction solution, andthe mixture was incubated at 30° C. for 45 minutes. Next, theposttranslational reaction solutions of the H chain (or L chain) libraryand the L chain (or H chain) were mixed and further incubated at 30° C.for 90 minutes to prepare H chain (or L chain) ribosome display Fabs.Then, the reaction was terminated by cooling to 4° C. Subsequently, anantigen was added to the reaction solution, and the mixture was gentlystirred at 4° C. for 1 hour so that each Fab bound to the antigen. Theantigen used was a formalin fixed sample of CHO cells constitutivelyexpressing human Orai1 which were established by use of pcDNA3.1-hOrai1prepared in 1)-1-1, or the biotin-PEGylated human Orai1 loop regionpeptide (Sigma-Aldrich Corp.) shown below.

Biotin-PEGylated human Orai1 loop region peptide Biotin-PEG-

(SEQ ID NO: 115) SGSGFLPLKKQPGQPRPTSKPPASGAAANVSTSGITPGQAAAIASTTI

The ribosome display Fabs bound with the antigen were recovered usingNonolink Streptavidin magnetic beads (SoluLink, Inc.). Subsequently, theantigen was washed with 50 mM Tris-HCl (pH 7.4), 150 mM NaCl, 15 mMMg(OAc)₂, 0.05% Tween 20, and 1 mg/mL yeast RNA, and with 50 mM Tris-HCl(pH 7.4), 150 mM NaCl, 15 mM Mg(OAc)₂, and 0.05% Tween 20. Then, 50 mMTris-HCl (pH 7.4), 150 mM NaCl, 15 mM Mg(OAc)₂, and 50 mM EDTA wereadded to the antigen, and the mixture was left standing at roomtemperature for 10 minutes, followed by the recovery of a supernatantcontaining mRNAs by centrifugation. cDNAs were formed from the recoveredmRNAs using a Transcriptor High Fidelity cDNA Synthesis Kit (F.Hoffmann-La Roche, Ltd.) and then amplified as DNAs by PCR using theprimer set given below and KOD -Plus-. mRNAs were synthesized with theDNAs as templates and further screened in the same way as above. Thescreening cycle was carried out plural times to select a gene of anantibody strongly binding to the antigen.

Primer Set

(SEQ ID NO: 50; primer Orail-LcF) 5′-ATGGACATTCAACTGACCCAAAGC-3′(SEQ ID NO: 54; primer Myc-R) 5′-CAGATCCTCCTCAGAGATCAGCTTCTGCTC-3′

9)-3 Preparation of Fab Protein

The selected genes were subcloned into vectors for expression in E. coliand screened by Cell ELISA for clones with improved binding activityagainst CHO cells constitutively expressing human Orai1. First, eachselected DNA was cleaved with restriction enzymes EcoRV and Xhol andinserted into a vector for Fab expression (GeneFrontier Corp.) cleavedwith the same enzymes as above, which was then transferred to E. coliBL21 (DE3). The transformants thus obtained were cultured at 37° C. for4 to 5 hours in 150 μL of carbenicillin/0.1% glucose/2× YT per well on around bottom 96-well plate. Next, the plate was cooled to 4° C., andthen, IPTG was added thereto at a final concentration of 0.5 mM,followed by overnight shake culture at 30° C. Next, the bacterial cellswere recovered by centrifugation, and then a lysis buffer (2.5 mg/mLlysozyme, 100 U DNase I) was added thereto, followed by shaking at roomtemperature for 60 minutes. Subsequently, supernatant was recovered bycentrifugation to prepare Fab samples.

9)-4 Screening by Cell ELISA

Cells expressing human Orai1 were cultured in a 384-well plate untilbecoming a confluent sheet. Then, the plate was washed with a washingbuffer (PBS(−), 20 mM MgSO₄, 2.5% FBS). Next, the Fab samples were addedto the plate, and the plate was shaken at 4° C. for 1 hour. Afterwashing four times with a washing buffer, a peroxidase labeledanti-human F(ab′)₂ goat antibody (Jackson ImmunoResearch Laboratories,Inc.) was added thereto, and the plate was shaken at 4° C. for 30minutes. The plate was washed three times with a washing buffer and thenwashed three times with PBS(−) and 20 mM MgSO₄. Then, a chromogenicreagent (0.4 mg/mL tetramethyl-benzidine, 200 mM sodium acetate (pH3.4), 0.01% aqueous hydrogen peroxide solution) was added thereto, andthe plate was shaken at room temperature for 15 minutes. Then, 2 N HClwas added thereto, followed by the measurement of OD₄₅₀. A Fab sampleexhibiting higher OD₄₅₀ against the CHO cells constitutively expressinghuman Orai1, as compared with control CHO cells, was selected.

9)-5 Antigen Binding Activity of Anti-Human Orai1 Antibody Fab by FlowCytometry

In order to evaluate human Orai1 binding specificity, the pcDNA3.1-DESTtransfected HEK293T cell suspension or the pcDNA3.1-hOrai1 transfectedHEK293T cell suspension prepared by the method shown in 1)-4-1 wascentrifuged to remove supernatant. Then, the HEK293T cells weresuspended by the addition of the light chain mutated clone LCDR60,LCDR67, LCDR83, CE151, or PE057 or the heavy chain mutated cloneHCDR046, HCDR047, HEP087, HEP124, or HEP237 selected in 9)-4, or theparent antibody Fab hR198_H4/L4-Fab, and left standing at 4° C. for 30minutes. The cells were washed twice with PBS containing 5% FBS, thensuspended by the addition of Anti-human IgG FITC conjugate diluted100-fold with PBS containing 5% FBS, and left standing at 4° C. for 30minutes. The cells were washed twice with PBS containing 5% FBS and thenresuspended in PBS containing 5% FBS and 1 μg/mL propidium iodide,followed by detection using a flow cytometer (FC500). The data wasanalyzed using Flowjo. After removal of propidium iodide positive deadcells by gating, the FITC fluorescence intensity of live cells wasplotted to a histogram to calculate mean fluorescence intensity (MFI).The light chain mutated clones LCDR60, LCDR67, LCDR83, CE151, and PE057and the heavy chain mutated clones HCDR046, HCDR047, HEP087, HEP124, andHEP237 did not bind to the pcDNA3.1-DEST transfected HEK293T cells, aswith the parent antibody Fab hR198_H4/L4-Fab, and, as shown in FIGS.7A-7C, each tended to bind to human Orai1 in the pcDNA3.1-hOrai1transfected HEK293T cells at a level equivalent to or stronger than thatof the parent antibody Fab.

[Example 10] Preparation of Affinity Maturation Antibody of HumanizedAnti-Human Orai1 Antibody

100 or more types of engineered hR198_H3/L3 antibodies were prepared bythe transfer of some of the activity enhancing mutations found in thelight chain mutated clones LCDR60, LCDR67, LCDR83, CE151, and PE057 andthe heavy chain mutated clones HCDR046, HCDR047, HEP087, HEP124, andHEP237 selected in Example 9) to hR198_H3/L3, and evaluated from theviewpoint of binding affinity, in vitro activity, productivity, andheterogeneous antigenicity against humans. As a result, antibodies shownbelow were selected.

10)-1 Design of Affinity Maturation Antibody of Humanized Anti-HumanOrai1 Antibody

10)-1-1 hR198_LG1 Type Light Chain:

A humanized R198 light chain designed by replacing an asparagine residueat amino acid position 51 with a glycine residue, a threonine residue atamino acid position 113 with an isoleucine residue, and a threonineresidue at amino acid position 117 with a serine residue as to thehR198_L3 light chain shown in SEQ ID NO: 35 of the Sequence Listing wasdesignated as a “hR198_LG1 type light chain”.

The nucleotide sequence encoding the hR198_LG1 type light chain is shownin SEQ ID NO: 55 of the Sequence Listing. Nucleotide positions 61 to 702encode a mature light chain formed by the cleavage of the signalsequence. Nucleotide positions 61 to 378 encode the variable region. Theamino acid sequence of the hR198_LG1 type light chain is shown in SEQ IDNO: 56 of the Sequence Listing. Amino acid positions 21 to 234 representthe mature light chain formed by the cleavage of the signal sequence.Amino acid positions 21 to 126 represent the variable region. Both ofthe sequences of SEQ ID NOs: 55 and 56 are also shown in FIG. 30. EachCDR sequence and its corresponding SEQ ID NO are shown in FIG. 38.

10)-1-2 hR198_LG2 Type Light Chain:

A humanized R198 light chain designed by replacing an arginine residueat amino acid position 44 with a histidine residue, a serine residue atamino acid position 48 with an asparagine residue, an asparagine residueat amino acid position 51 with a glycine residue, a serine residue atamino acid position 70 with a leucine residue, a glutamic acid residueat amino acid position 75 with an aspartic acid residue, a serineresidue at amino acid position 76 with a tryptophan residue, a threonineresidue at amino acid position 113 with an isoleucine residue, and athreonine residue at amino acid position 117 with a serine residue as tothe hR198_L3 light chain shown in SEQ ID NO: 35 of the Sequence Listingwas designated as a “hR198_LG2 type light chain”.

The nucleotide sequence encoding the hR198_LG2 type light chain is shownin SEQ ID NO: 57 of the Sequence Listing. Nucleotide positions 61 to 702encode a mature light chain formed by the cleavage of the signalsequence. Nucleotide positions 61 to 378 encode the variable region. Theamino acid sequence of the hR198_LG2 type light chain is shown in SEQ IDNO: 58 of the Sequence Listing. Amino acid positions 21 to 234 representthe mature light chain formed by the cleavage of the signal sequence.Amino acid positions 21 to 126 represent the variable region. Both ofthe sequences of SEQ ID NOs: 57 and 58 are also shown in FIG. 31. EachCDR sequence and its corresponding SEQ ID NO are shown in FIG. 38.

10)-1-3 hR198_LG3 Type Light Chain:

A humanized R198 light chain designed by replacing an arginine residueat amino acid position 44 with a histidine residue, a glutamine residueat amino acid position 47 with an arginine residue, a serine residue atamino acid position 48 with an asparagine residue, an asparagine residueat amino acid position 51 with a glycine residue, a serine residue atamino acid position 70 with a leucine residue, a threonine residue atamino acid position 73 with a serine residue, a glutamic acid residue atamino acid position 75 with an aspartic acid residue, a serine residueat amino acid position 76 with a tryptophan residue, a threonine residueat amino acid position 113 with an isoleucine residue, and a threonineresidue at amino acid position 117 with a serine residue as to thehR198_L3 light chain shown in SEQ ID NO: 35 of the Sequence Listing wasdesignated as a “hR198_LG3 type light chain”.

The nucleotide sequence encoding the hR198_LG3 type light chain is shownin SEQ ID NO: 59 of the Sequence Listing. Nucleotide positions 61 to 702encode a mature light chain formed by the cleavage of the signalsequence. Nucleotide positions 61 to 378 encode the variable region. Theamino acid sequence of the hR198_LG3 type light chain is shown in SEQ IDNO: 60 of the Sequence Listing. Amino acid positions 21 to 234 representthe mature light chain formed by the cleavage of the signal sequence.Amino acid positions 21 to 126 represent the variable region. Both ofthe sequences of SEQ ID NOs: 59 and 60 are also shown in FIG. 32. EachCDR sequence and its corresponding SEQ ID NO are shown in FIG. 38.

10)-1-4 hR198_HG1 Type Heavy Chain:

A humanized R198 heavy chain designed by replacing an asparagine residueat amino acid position 78 with an aspartic acid residue, and a valineresidue at amino acid position 123 with an alanine residue as to thehR198_H3 heavy chain shown in SEQ ID NO: 43 of the Sequence Listing wasdesignated as a “hR198_HG1 type heavy chain”.

The nucleotide sequence encoding the hR198_HG1 type heavy chain is shownin SEQ ID NO: 61 of the Sequence Listing. Nucleotide positions 58 to1398 encode a mature heavy chain formed by the cleavage of the signalsequence. Nucleotide positions 58 to 408 encode the variable region. Theamino acid sequence of the hR198_HG1 type heavy chain is shown in SEQ IDNO: 62 of the Sequence Listing. Amino acid positions 20 to 466 representthe mature heavy chain formed by the cleavage of the signal sequence.Amino acid positions 20 to 135 represent the variable region. Both ofthe sequences of SEQ ID NOs: 61 and 62 are also shown in FIG. 33. EachCDR sequence and its corresponding SEQ ID NO are shown in FIG. 38.

10)-1-5 hR198_HG2 Type Heavy Chain:

A humanized R198 heavy chain designed by replacing a valine residue atamino acid position 48 with an isoleucine residue, an asparagine residueat amino acid position 78 with an aspartic acid residue, an alanineresidue at amino acid position 81 with a glycine residue, and a valineresidue at amino acid position 123 with an alanine residue as to thehR198_H3 heavy chain shown in SEQ ID NO: 43 of the Sequence Listing wasdesignated as a “hR198_HG2 type heavy chain”.

The nucleotide sequence encoding the hR198_HG2 type heavy chain is shownin SEQ ID NO: 63 of the Sequence Listing. Nucleotide positions 58 to1398 encode a mature heavy chain formed by the cleavage of the signalsequence. Nucleotide positions 58 to 408 encode the variable region. Theamino acid sequence of the hR198_HG2 type heavy chain is shown in SEQ IDNO: 64 of the Sequence Listing. Amino acid positions 20 to 466 representthe mature heavy chain formed by the cleavage of the signal sequence.Amino acid positions 20 to 135 represent the variable region. Both ofthe sequences of SEQ ID NOs: 63 and 64 are also shown in FIG. 34. EachCDR sequence and its corresponding SEQ ID NO are shown in FIG. 38.

10)-1-6 hR198_HG3 Type Heavy Chain:

A humanized R198 heavy chain designed by replacing a valine residue atamino acid position 48 with an isoleucine residue, an asparagine residueat amino acid position 78 with an aspartic acid residue, an alanineresidue at amino acid position 81 with a methionine residue, and avaline residue at amino acid position 123 with an alanine residue as tothe hR198_H3 heavy chain shown in SEQ ID NO: 43 of the Sequence Listingwas designated as a “hR198_HG3 type heavy chain”.

The nucleotide sequence encoding the hR198_HG3 type heavy chain is shownin SEQ ID NO: 65 of the Sequence Listing. Nucleotide positions 58 to1398 encode a mature heavy chain formed by the cleavage of the signalsequence. Nucleotide positions 58 to 408 encode the variable region. Theamino acid sequence of the hR198_HG3 type heavy chain is shown in SEQ IDNO: 66 of the Sequence Listing. Amino acid positions 20 to 466 representthe mature heavy chain formed by the cleavage of the signal sequence.Amino acid positions 20 to 135 represent the variable region. Both ofthe sequences of SEQ ID NOs: 65 and 66 are also shown in FIG. 35. EachCDR sequence and its corresponding SEQ ID NO are shown in FIG. 38.

10)-2 Preparation of Affinity Maturation Antibody Expression Vector ofHumanized Anti-Human Orai1 Antibody 10)-2-1 Construction of hR198_LG1Type Light Chain Expression Vector

Mutations to replace an asparagine residue at amino acid position 51with a glycine residue, a threonine residue at amino acid position 113with an isoleucine residue, and a threonine residue at amino acidposition 117 with a serine residue were introduced with pCMA-LK/hR198_L3as the template using KOD -Plus- mutagenesis. The obtained expressionvector comprising the nucleotide sequence represented by SEQ ID NO: 55of the Sequence Listing was designated as “pCMA-LK/hR198_LG1”.

10)-2-2 Construction of hR198_LG2 and LG3 Type Light Chain ExpressionVectors

A DNA fragment comprising the hR198_LG3variable-region-encoding-sequence shown in nucleotide positions 38 to402 in the nucleotide sequence of hR198_LG3 represented by SEQ ID NO: 59of the Sequence Listing was synthesized (GeneArt Artificial GeneSynthesis service). The synthesized DNA fragment was cleaved withrestriction enzymes EcoRV and AvaI and inserted to pCMA-LK/hR198_LG1cleaved with the same restriction enzymes as above to construct ahR198_LG3 expression vector. The obtained expression vector wasdesignated as “pCMA-LK/hR198_LG3”.

Mutations to replace an arginine residue at amino acid position 47 witha glutamine residue and a serine residue at amino acid position 73 witha threonine residue were introduced with pCMA-LK/hR198_LG3 as thetemplate using KOD -Plus- mutagenesis. The obtained expression vectorcomprising the nucleotide sequence represented by SEQ ID NO: 57 of theSequence Listing was designated as “pCMA-LK/hR198_LG2”.

10)-2-3 Construction of hR198_HG1 Type Heavy Chain Expression Vector

Mutations to replace an asparagine residue at amino acid position 78with an aspartic acid residue and a valine residue at amino acidposition 123 with an alanine residue were introduced withpCMA-G1/hR198_H3 as the template using KOD -Plus- mutagenesis. Theobtained expression vector comprising the nucleotide sequencerepresented by SEQ ID NO: 61 of the Sequence Listing was designated as“pCMA-G1/hR198_HG1”.

10)-2-4 Construction of hR198_HG2 Type Heavy Chain Expression Vector

Mutations to replace a valine residue at amino acid position 48 with anisoleucine residue and an alanine residue at amino acid position 81 witha glycine residue were introduced with pCMA-G1/hR198_HG1 as the templateusing KOD -Plus- mutagenesis. The obtained expression vector comprisingthe nucleotide sequence represented by SEQ ID NO: 63 of the SequenceListing was designated as “pCMA-G1/hR198_HG2”.

10)-2-5 Construction of hR198_HG3 Type Heavy Chain Expression Vector

A mutation to replace a glycine residue at amino acid position 81 with amethionine residue was introduced with pCMA-G1/hR198_HG2 as the templateusing KOD -Plus-mutagenesis. The obtained expression vector comprisingthe nucleotide sequence represented by SEQ ID NO: 65 of the SequenceListing was designated as “pCMA-G1/hR198_HG3”.

10)-3 Preparation of Affinity Maturation Antibody of HumanizedAnti-Human Orai1 Antibody

FreeStyle 293F cells were transfected with each humanized anti-humanOrai1 antibody heavy chain expression vector and each humanizedanti-human Orai1 antibody light chain expression vector prepared in10)-2 by the same method as in 4)-5-1 to obtain a culture supernatantcontaining the antibody.

Humanized anti-human Orai1 antibodies obtained by the combination of thetemplated pCMA-G1/hR198_H3 or pCMA-G1/hR198_HG1, pCMA-G1/hR198_HG2, orpCMA-G1/hR198_HG3 containing the mutation(s) with pCMA-LK/hR198_LG1,pCMA-LK/hR198_LG2, or pCMA-LK/hR198_LG3 were designated as“hR198_H3/LG1”, “hR198_HG1/LG1”, “hR198_HG1/LG2”, “hR198_HG1/LG3”,“hR198_HG2/LG1”, and “hR198_HG3/LG1”, respectively.

Each obtained culture supernatant was purified by rProtein A affinitychromatography by the same method as in 4)-5-2 to obtain a purifiedantibody sample.

[Example 11] In Vitro Activity of Affinity Maturation Antibody

11)-1 Evaluation of Ability of Affinity Maturation Antibody to Bind byFlow Cytometry

In order to evaluate human Orai1 binding specificity, the pcDNA3.1-DESTtransfected HEK293T cell suspension or the pcDNA3.1-hOrai1 transfectedHEK293T cell suspension prepared by the method shown in 1)-4-1 wascentrifuged to remove supernatant. Then, the HEK293T cells weresuspended by the addition of the affinity maturation antibodyhR198_H3/LG1, hR198_HG1/LG1, hR198_HG1/LG2, hR198_HG1/LG3,hR198_HG2/LG1, or hR198_HG3/LG1 prepared in 10)-3 or the parent antibodyhR198_H3/L3 or hR198_H4/L4, and incubated at 4° C. for 30 minutes. Thecells were washed twice with PBS containing 5% FBS, then suspended bythe addition of Anti-human IgG FITC conjugate diluted 100-fold with PBScontaining 5% FBS, and incubated at 4° C. for 30 minutes. The cells werewashed twice with PBS containing 5% FBS and then resuspended in PBScontaining 5% FBS and 1 μg/mL propidium iodide, followed by detectionusing a flow cytometer (FC500). The data was analyzed using Flowjo.After exclusion of propidium iodide positive dead cells by gating, theFITC fluorescence intensity of live cells was plotted as a histogram tocalculate mean fluorescence intensity (MFI). The affinity maturationantibodies hR198_H3/LG1, hR198_HG1/LG1, hR198_HG1/LG2, hR198_HG1/LG3,hR198_HG2/LG1, and hR198_HG3/LG1 did not bind to the pcDNA3.1-DESTtransfected HEK293T cells, as with the parent antibody hR198_H3/L3 orhR198_H4/L4, and, as shown in FIG. 8, each tended to bind to human Orai1in the pcDNA3.1-hOrai1 transfected HEK293T cells at a level equivalentto or stronger than that of the parent antibody.

11)-2 T Cell Activation Inhibitory Effect of Affinity MaturationAntibody

Human T cell line Jurkat cells were prepared at a concentration of1.5×10⁶ cells/mL in RPMI1640 containing 10% FBS, 100 U/mL penicillin,and 100 μg/mL streptomycin, inoculated at 80 μL/well onto a 96-well cellculture plate, and pretreated with the affinity maturation antibodyhR198_H3/LG1, hR198_HG1/LG1, hR198_HG1/LG2, hR198_HG1/LG3,hR198_HG2/LG1, or hR198_HG3/LG1 or the humanized anti-human Orai1antibody hR198_H3/L3 or hR198_H4/L4 added at 10 μL/well at 37° C. for 60minutes under 5% CO₂ conditions. Then, 100 ng/mL PMA and 1 μg/mL A23187were added at 10 μL/well and well stirred, followed by culture at 37° C.for approximately 16 hours under 5% CO₂ conditions. The plate was wellstirred and then centrifuged at 600 g for 3 minutes. The IL-2concentration contained in the supernatant was measured by ELISA. FIG. 9shows that the affinity maturation antibodies each inhibit, in aconcentration dependent manner, the release of IL-2 from Jurkat cellstreated with PMA and A23187. The affinity maturation antibodies eachinhibited the IL-2 release from the Jurkat cells in a concentrationdependent manner and were all superior in inhibitory activity to thehumanized anti-human Orai1 antibodies hH3/L3 and hH4/L4, which wereparent antibodies.

[Example 12] Preparation of Engineered Form with Reduced EffectorActivity of Affinity Maturation Antibody

A constant region engineered hR198_HG1-LALA sequence derived fromhR198_HG1 by the substitution of two amino acid residues in the constantregion was constructed as described in the Examples below.

12)-1 Design of LALA Type Heavy Chain Expression Vector

For circumventing cytotoxicity against normal cells expressing humanOrai1, it is desirable that an antibody should have low effectoractivity. The effector activity is known to differ among antibodysubclasses. The following characteristics are observed, for example,IgG4 has low ADCC and CDC activities, and IgG2 has CDC activity, but haslow ADCC activity. On the basis of these features, it is possible toprepare an IgG1 antibody with reduced ADCC and CDC activities bypartially substituting the constant region sequences of IgG1 withreference to IgG2 or IgG4. As one example, Marjan Hezareh et al.,Journal of Virology, 75 (24): 12161-12168 (2001) shows that the ADCC andCDC activities of IgG1 are reduced by replacing each of the leucineresidues at positions 234 and 235 (the positions are indicated by the EUindex of Kabat et al.) of IgG1 with an alanine residue. Accordingly, ahumanized anti-human Orai1 antibody heavy chain designed by replacing aleucine residue at amino acid position 253 with an alanine residue and aleucine residue at amino acid position 254 with an alanine residue as tothe hR198_HG1 type heavy chain prepared in 10)-1 was designated as a“hR198_HG1-LALA type heavy chain”.

12)-2 Construction of LALA Type Heavy Chain Expression Vector

12)-2-1 Construction of hR198_HG1-LALA Type Heavy Chain ExpressionVector

The mutations were introduced with the hR198_H4 type heavy chainpCMA-G1/hR198_H4 prepared in 7)-2 as a template using a KOD -Plus-Mutagenesis Kit to construct a hR198_H4-LALA type heavy chain expressionvector. The obtained expression vector was designated as“pCMA-G1-LALA/hR198_H4”. The nucleotide sequence encoding thehR198_H4-LALA type heavy chain and the amino acid sequence of the heavychain are shown in SEQ ID NOs: 67 and 68 (FIG. 36), respectively, of theSequence Listing.

A DNA fragment of approximately 0.6 kb comprising the antibodyvariable-region-encoding-sequence was obtained by the digestion ofpCMA-G1/hR198_HG1 prepared in 10)-2 with restriction enzymes PstI andXbaI, and inserted into a DNA fragment of approximately 4.2 kb obtainedby the digestion of pCMA-G1-LALA/hR198_H4 with the same restrictionenzymes as above using Ligation High ver. 2 to construct ahR198_HG1-LALA type heavy chain expression vector. The obtainedexpression vector was designated as “pCMA-G1-LALA/hR198_HG1”. Thenucleotide sequence encoding the hR198_HG1-LALA type heavy chain and theamino acid sequence of the heavy chain are shown in SEQ ID NOs: 69 and70 (FIG. 37), respectively, of the Sequence Listing.

12)-3 Preparation of Engineered Form with Reduced Effector Activity ofAffinity Maturation Antibody

12)-3-1 Production of Engineered Form with Reduced Effector Activity ofAffinity Maturation Antibody

FreeStyle 293F cells (Life Technologies Corp.) were subcultured andcultured according to the manual. 1.2×10⁹ FreeStyle 293F cells (LifeTechnologies Corp.) in the logarithmic growth phase were inoculated to 3L Fernbach Erlenmeyer Flask (Corning Inc.), prepared at 1.0×10⁶ cells/mLby dilution with FreeStyle 293 expression medium (Invitrogen Corp.), andthen shake cultured at 90 rpm at 37° C. for 1 hour in an 8% CO₂incubator. 3.6 mg of polyethyleneimine (Polysciences #24765) wasdissolved in 20 mL of Opti-Pro SFM (Life Technologies Corp.). Next, eachlight chain expression vector (0.8 mg) and each heavy chain expressionvector (0.4 mg) prepared using PureLink HiPure Plasmid kit (LifeTechnologies Corp.) were added to 20 mL of Opti-Pro SFM (LifeTechnologies Corp.). 20 mL of the expression vector/Opti-Pro SFM mixedsolution was added to 20 ml of the polyethyleneimine/Opti-Pro SFM mixedsolution, and the mixture was gently stirred, further left for 5minutes, and then added to the FreeStyle 293F cells. The cells wereshake cultured at 90 rpm at 37° C. for 7 days in an 8% CO₂ incubator,and the obtained culture supernatant was filtered through DisposableCapsule Filter (ADVANTEC #CCS-045-E1H). hR198_HG1/LG1 was produced bythe combination of pCMA-G1/hR198_HG1 and pCMA-LK/hR198_LG1, andhR198_HG1-LALA/LG1 was produced by the combination ofpCMA-G1-LALA/hR198_HG1 and pCMA-LK/hR198_LG1.

12)-3-2 Purification in Two Steps of Engineered Form with ReducedEffector Activity of Affinity Maturation Antibody

Each antibody was purified from the culture supernatant obtained inExample 12)-3-1 in two steps using rProtein A affinity chromatography(at 4 to 6° C.) and ceramic hydroxyapatite (at room temperature). Thebuffer replacement step after the purification by rProtein A affinitychromatography and after the purification by ceramic hydroxyapatite wascarried out at 4 to 6° C. The culture supernatant was applied toMabSelectSuRe (GE Healthcare Bio-Sciences Corp., HiTrap column)equilibrated with PBS. After entry of the whole culture supernatant inthe column, the column was washed with PBS in 2 or more times the volumeof the column. Next, fractions containing the antibody were collected byelution with a 2 M arginine hydrochloride solution (pH 4.0). The buffersof the fractions were replaced with PBS by dialysis (Thermo FisherScientific Inc., Slide-A-Lyzer Dialysis Cassette) and then diluted5-fold with a buffer of 5 mM sodium phosphate/50 mM MES (pH 7.0). Theresulting antibody solution was applied to a ceramic hydroxyapatitecolumn (Bio-Rad Laboratories, Inc., Bio-Scale CHT Type-1 HydroxyapatiteColumn) equilibrated with a buffer of 5 mM NaPi/50 mM MES/30 mM NaCl (pH7.0). Fractions containing the antibody were collected by linearconcentration gradient elution with sodium chloride. The buffers of thefractions were replaced with HBSor (25 mM histidine/5% sorbitol, pH 6.0)by dialysis (Thermo Fisher Scientific Inc., Slide-A-Lyzer DialysisCassette). The solution was concentrated into an IgG concentration of 5mg/mL or higher using Centrifugal UF Filter Device VIVASPIN 20(molecular weight cutoff: UF10K, Sartorius Japan K.K., 4° C.) Finally,the antibody solution was filtered through Minisart-Plus filter(Sartorius Japan K.K.) and used as a purified sample.

[Example 13] Preparation of Human Anti-Human Orai1 Antibody 2C1.1 and5H3.1 Expression Vectors

2C1.1 and 5H3.1 antibodies were prepared on the basis of the amino acidsequences of light and heavy chains described in WO2011063277A1.

13)-1 Construction of Chimerized and Humanized IgG2 Type Heavy ChainExpression Vector pCMA-G2

A DNA fragment obtained by the digestion of pCMA-LK with XbaI and PmeIto remove the sequence encoding a κ chain secretion signal and a human κchain constant region was ligated with a DNA fragment (shown in SEQ IDNO: 71 of the Sequence Listing) comprising a sequence encoding a humanheavy chain secretion signal and amino acids of a human IgG2 constantregion using In-Fusion Advantage PCR cloning kit to construct a chimericand humanized IgG2 type heavy chain expression vector pCMA-G2 having asignal sequence, a cloning site, and the human IgG2 heavy chainconstant-region-encoding-sequence downstream of a CMV promoter.

13)-2 Construction of 2C1.1 Antibody Heavy Chain Expression Vector

A DNA fragment comprising the 2C1.1 antibody heavy chainvariable-region-encoding-sequence shown in nucleotide positions 36 to434 in the 2C1.1 antibody heavy chain encoding nucleotide sequencerepresented by SEQ ID NO: 72 of the Sequence Listing was synthesized(GeneArt Artificial Gene Synthesis service). The DNA fragment comprisingthe 2C1.1 antibody heavy chain variable region encoding sequence wasamplified with the synthesized DNA fragment as a template using KOD-Plus- and inserted into the corresponding site of the chimeric andhumanized antibody IgG2 type heavy chain expression vector pCMA-G2cleaved with a restriction enzyme BlpI using an In-Fusion HD PCR cloningkit to construct a 2C1.1 antibody heavy chain expression vector. Theobtained expression vector was designated as “pCMA-G2/2C1.1”.

The amino acid sequence of the 2C1.1 antibody heavy chain is shown inSEQ ID NO: 73 of the Sequence Listing.

13)-3 Construction of 2C1.1 Antibody Light Chain Expression Vector

A DNA fragment comprising the 2C1.1 antibody light chain variable regionand constant region (λ chain) encoding sequences shown in nucleotidepositions 38 to 739 in the 2C1.1 antibody lightchain-encoding-nucleotide-sequence represented by SEQ ID NO: 74 of theSequence Listing was synthesized (GeneArt Artificial Gene Synthesisservice). The DNA fragment comprising the 2C1.1 antibody light chainvariable region and constant region-encoding sequences was amplifiedwith the synthesized DNA fragment as a template using KOD -Plus- andinserted into the corresponding site of the chimeric and humanizedantibody light chain expression vector pCMA-LK cleaved with restrictionenzymes BsiWI and PmeI using an In-Fusion HD PCR cloning kit toconstruct a 2C1.1 antibody light chain expression vector. The obtainedexpression vector was designated as “pCMA-L/2C1.1”.

The amino acid sequence of the 2C1.1 antibody light chain is shown inSEQ ID NO: 75 of the Sequence Listing.

13)-4 Construction of 5H3.1 Antibody Heavy Chain Expression Vector

A DNA fragment comprising the 5H3.1 antibody heavy chainvariable-region-encoding-sequence shown in nucleotide positions 36 to434 in the 5H3.1 antibody heavy chain encoding nucleotide sequencerepresented by SEQ ID NO: 76 of the Sequence Listing was synthesized(GeneArt Artificial Gene Synthesis service). A 5H3.1 antibody heavychain expression vector was constructed by the same method as in Example13)-2. The obtained expression vector was designated as “pCMA-G2/5H3.1”.

The amino acid sequence of the 5H3.1 antibody heavy chain is shown inSEQ ID NO: 77 of the Sequence Listing.

13)-5 Construction of 5H3.1 Antibody Light Chain Expression Vector

A DNA fragment comprising the 5H3.1 antibody light chain variable regionand constant region-encoding sequences shown in nucleotide positions 38to 742 in the 5H3.1 antibody light chain encoding nucleotide sequencerepresented by SEQ ID NO: 78 of the Sequence Listing was synthesized(GeneArt Artificial Gene Synthesis service). A 5H3.1 antibody lightchain expression vector was constructed by the same method as in Example13)-3. The obtained expression vector was designated as “pCMA-L/5H3.1”.

The amino acid sequence of the 5H3.1 antibody light chain is shown inSEQ ID NO: 79 of the Sequence Listing.

13)-6 Preparation of 2C1.1 and 5H3.1 Antibodies

13)-6-1 Production of 2C1.1 and 5H3.1 Antibodies

Each antibody was produced by the same method as in Example 12)-3-1. The2C1.1 antibody was produced by the combination of pCMA-G2/2C1.1 andpCMA-L/2C1.1, and the 5H3.1 antibody was produced by the combination ofpCMA-G2/5H3.1 and pCMA-L/5H3.1.

13)-6-2 Purification in Two Steps of 2C1.1 and 5H3.1 Antibodies

Each antibody was purified in two steps by the same method as in Example12)-3-2 from the culture supernatant produced in Example 13)-6-1.

[Example 14] Preparation of Mouse Anti-Human Orai1 Antibodies 10F8,14F74, and 17F6

10F8, 14F74, and 17F6 antibodies were prepared on the basis of the aminoacid sequences of light and heavy chains described in WO2013091903A1.

14)-1 Construction of 10F8 Antibody Heavy Chain Expression Vector

A DNA fragment comprising the 10F8 antibody heavy chain-encodingnucleotide sequence represented by SEQ ID NO: 80 of the Sequence Listingwas synthesized (GeneArt Artificial Gene Synthesis service). The DNAfragment comprising the 10F8 antibody heavy chain-encoding sequence wasamplified with the synthesized DNA fragment as a template using KOD-Plus- and inserted into the site from which the sequence encoding a κchain secretion signal and a human κ chain constant region was removedby the digestion of the chimeric and humanized antibody light chainexpression vector pCMA-LK with restriction enzymes XbaI and PmeI, usingan In-Fusion HD PCR cloning kit to construct a 10F8 antibody heavy chainexpression vector. The obtained expression vector was designated as“pCMA/10F8H”.

The amino acid sequence of the 10F8 antibody heavy chain is shown in SEQID NO: 81 of the Sequence Listing.

14)-2 Construction of 10F8 Antibody Light Chain Expression Vector

A DNA fragment comprising the 10F8 antibody light chain encodingnucleotide sequence represented by SEQ ID NO: 82 of the Sequence Listingwas synthesized (GeneArt Strings DNA Fragments). The synthesized DNAfragment inserted into the site from which the sequence encoding a κchain secretion signal and a human κ chain constant region was removedby the digestion of the chimeric and humanized antibody light chainexpression vector pCMA-LK with restriction enzymes XbaI and PmeI, usingan In-Fusion HD PCR cloning kit to construct a 10F8 antibody light chainexpression vector. The obtained expression vector was designated as“pCMA/10F8L”.

The amino acid sequence of the 10F8 antibody light chain is shown in SEQID NO: 83 of the Sequence Listing.

14)-3 Construction of 14F74 Antibody Heavy Chain Expression Vector

A DNA fragment comprising the 14F74 antibody heavy chain encodingnucleotide sequence represented by SEQ ID NO: 84 of the Sequence Listingwas synthesized (GeneArt Artificial Gene Synthesis service). A 14F74antibody heavy chain expression vector was constructed by the samemethod as in Example 14)-1. The obtained expression vector wasdesignated as “pCMA/14F74H”.

The amino acid sequence of the 14F74 antibody heavy chain is shown inSEQ ID NO: 85 of the Sequence Listing.

14)-4 Construction of 14F74 Antibody Light Chain Expression Vector

A DNA fragment comprising the 14F74 antibody light chain-encodingnucleotide sequence represented by SEQ ID NO: 86 of the Sequence Listingwas synthesized (GeneArt Strings DNA Fragments). A 14F74 antibody lightchain expression vector was constructed by the same method as in Example14)-2. The obtained expression vector was designated as “pCMA/14F74L”.

The amino acid sequence of the 14F74 antibody light chain is shown inSEQ ID NO: 87 of the Sequence Listing.

14)-5 Construction of 17F6 Antibody Heavy Chain Expression Vector

A DNA fragment comprising the 17F6 antibody heavy chain-encodingnucleotide sequence represented by SEQ ID NO: 88 of the Sequence Listingwas synthesized (GeneArt Artificial Gene Synthesis service). A 17F6antibody heavy chain expression vector was constructed by the samemethod as in Example 14)-1. The obtained expression vector wasdesignated as “pCMA/17F6H”.

The amino acid sequence of the 17F6 antibody heavy chain is shown in SEQID NO: 89 of the Sequence Listing.

14)-6 Construction of 17F6 Antibody Light Chain Expression Vector

A DNA fragment comprising the 17F6 antibody light chain-encodingnucleotide sequence represented by SEQ ID NO: 90 of the Sequence Listingwas synthesized (GeneArt Strings DNA Fragments). A 17F6 antibody lightchain expression vector was constructed by the same method as in Example14)-2. The obtained expression vector was designated as “pCMA/17F6L”.

The amino acid sequence of the 17F6 antibody light chain is shown in SEQID NO: 91 of the Sequence Listing.

14)-7 Preparation of 10F8, 14F74, and 17F6 Antibodies

14)-7-1 Production of 10F8, 14F74, and 17F6 Antibodies

Each antibody was produced by the same method as in Example 12)-3-1. The10F8 antibody was produced by the combination of pCMA/10F8H andpCMA/10F8L. The 14F74 antibody was produced by the combination ofpCMA/14F74H and pCMA/14F74L. The 17F6 antibody was produced by thecombination of pCMA/17F6H and pCMA/17F6L.

14)-7-2 Purification in Two Steps of 10F8, 14F74, and 17F6 Antibodies

Each antibody was purified in two steps by the same method as in Example12)-3-2 from the culture supernatant obtained in Example 14)-7-1.

[Example 15] In Vitro Activity Comparison of Engineered Form withReduced Effector Activity of Affinity Maturation Antibody with OtherAnti-Human Orai1 Antibodies

15)-1 Antigen Binding Activity of Anti-Human Orai1 Antibody by FlowCytometry

A cell suspension of HEK293T cells transfected by the method shown in1)-4-2 with each human Orai1 expression vector constructed in 1)-1-1 wascentrifuged to remove a supernatant. Then, the pcDNA3.1-hOrai1transfected HEK293T cells or the pcDNA3.1-DEST transfected HEK293T cellswere suspended by the addition of hR198_HG1/LG1 or hR198_HG1/LG1-LALAprepared in 12)-3, 2C1.1 or 5H3.1 prepared in 13)-6, 10F8, 14F74, or17F6 prepared in 14)-7, or a human IgG control antibody or a mouse IgGcontrol antibody as a control, and incubated at 4° C. for 30 minutes.The cells were washed twice with PBS containing 5% FBS, then suspendedby the addition of Anti-human IgG FITC conjugate diluted 100-fold withPBS containing 5% FBS for the human antibodies or Anti-mouse IgG FITCconjugate (Cappel Laboratories, Inc.) for the mouse antibodies, andincubated at 4° C. for 30 minutes. The cells were washed twice with PBScontaining 5% FBS and then resuspended in PBS containing 5% FBS and 1μg/mL propidium iodide, followed by detection using a flow cytometer(FC500). The data was analyzed using Flowjo. After exclusion ofpropidium iodide positive dead cells by gating, the FITC fluorescenceintensity of live cells was plotted as a histogram to calculate meanfluorescence intensity (MFI). hR198_HG1/LG1, hR198_HG1-LALA/LG1, 2C1.1,5H3.1, 10F8, 14F74, and 17F6 did not bind to the pcDNA3.1-DESTtransfected HEK293T cells, and, as shown in FIG. 10 (human antibodies)and FIG. 11 (mouse antibodies), each bound to the pcDNA3.1-hOrai1transfected HEK293T cells, demonstrating that all of these antibodiesspecifically bind to human Orai1. On the other hand, no such binding wasobserved in the mouse IgG control antibody.

15)-2 Human T Cell Line Activation Inhibitory Effect of Anti-Human Orai1Antibody

Human T cell line Jurkat cells were prepared at a concentration of1.5×10⁶ cells/mL in RPMI1640 (containing 10% FBS, 100 U/mL penicillin,and 100 μg/mL streptomycin), inoculated at 80 μL/well to a 96-well cellculture plate, and pretreated with hR198_HG1/LG1, hR198_HG1-LALA/LG1,2C1.1, 5H3.1, 10F8, 14F74, or 17F6 added at 10 μL/well at 37° C. for 60minutes under 5% CO₂ conditions. Then, 100 ng/mL PMA and 1 μg/mL A23187were added at 10 μL/well (final concentration: 10 ng/mL PMA and 100ng/mL A23187) and well stirred, followed by culture at 37° C. forapproximately 16 hours under 5% CO₂ conditions. The plate was wellstirred and then centrifuged at 600 g for 3 minutes. The IL-2concentration contained in the supernatant was measured by ELISA. FIG.12 shows that the anti-human Orai1 antibodies each inhibit, in aconcentration dependent manner, the release of IL-2 from Jurkat cellstreated with PMA and A23187. FIG. 13 shows the half maximal inhibitoryconcentrations (IC₅₀) and the 80% inhibitory concentrations (IC₈₀) ofhR198_HG1/LG1, hR198_HG1-LALA/LG1, 2C1.1, 5H3.1, 10F8, 14F74, and 17F6with the IL-2 concentration in the absence of the antibody defined as100%. IC₅₀ of the antibodies of the prior techniques was 80 ng/mL orhigher, whereas IC₅₀ of the typical antibodies of the present inventionwas 10 ng/mL or lower. IC₈₀ of the antibodies of the prior techniqueswas 60000 ng/mL or higher, whereas IC_(H) of the typical antibodies ofthe present invention was 200 ng/mL or lower.

15)-3 Human Peripheral Blood Mononuclear Cell Activation InhibitoryEffects of Engineered Form with Reduced Effector Activity of AffinityMaturation Antibody and Other Anti-Human Orai1 Antibodies

Human peripheral blood mononuclear cells (PBMC) were purchased as afrozen product from Cellular Technology Ltd. and used after being thawedaccording to the instruction manual. PBMC prepared at a concentration of2.0×10⁶ cells/mL in RPMI1640 containing 10% FBS, 100 U/mL penicillin,and 100 μg/mL streptomycin was inoculated at 80 μL/well onto a 96-wellcell culture plate, and pretreated with each anti-human Orai1 antibodyadded at 10 μL/well for 60 minutes in an incubator at 37° C. Then, 100ng/mL PMA and 1 μg/mL A23187 were added at 10 μL/well and well stirred,followed by culture at 37° C. for approximately 16 hours under 5% CO₂conditions. The plate was well stirred and then centrifuged at 600 g for3 minutes. The IL-2 concentration and the interferon gamma (IFN-γ)concentration (Mabtech AB) contained in the supernatant were measured byELISA. FIG. 51 shows that the anti-human Orai1 antibodies each inhibit,in a concentration dependent manner, the release of IL-2 from human PBMCtreated with PMA and A23187. FIG. 52 shows the half maximal inhibitoryconcentrations (IC₅₀) and the 80% inhibitory concentrations (IC₈₀) ofhR198_HG1/LG1, hR198_HG1-LALA/LG1, 2C1.1, 5H3.1, 10F8, 14F74, and 17F6with the IL-2 concentration in the absence of the antibody defined as100%. IC₅₀ of the antibodies of the prior techniques was 100 ng/mL orhigher, whereas IC₅₀ of the typical antibodies of the present inventionwas 20 ng/mL or lower. IC₈₀ of the antibodies of the prior techniqueswas 17000 ng/mL or higher, whereas IC₈₀ of the typical antibodies of thepresent invention was 400 ng/mL or lower. FIG. 53 shows that theanti-human Orai1 antibodies each inhibit, in a concentration dependentmanner, the release of IFN-γ from human PBMC treated with PMA andA23187. FIG. 54 shows the half maximal inhibitory concentrations (IC₅₀)and the 80% inhibitory concentrations (IC₈₀) of hR198_HG1/LG1,hR198_HG1-LALA/LG1, 2C1.1, 5H3.1, 10F8, 14F74, and 17F6 with the IFN-γconcentration in the absence of the antibody defined as 100%. IC₅₀ ofthe antibodies of the prior techniques was 800 ng/mL or higher, whereasIC₅₀ of the typical antibodies of the present invention was 40 ng/mL orlower. IC₈₀ of the antibodies of the prior techniques was 300000 ng/mLor higher, whereas IC_(H) of the typical antibodies of the presentinvention was 2000 ng/mL or lower.

[Example 16] In Vivo Activity of hR198_HG1/LG1

16)-1 Effect of Administration of hR198_HG1/LG1 on Human PBMCTransplanted Mouse Graft Versus Host Disease Model

It is known that human graft versus host disease-like reaction can beinduced by the transplantation of human PBMC to NSG mice(NOD.Cg-Prkdc^(scid)Il2rg^(tm1Wjl)/SzJ), which are severe combinedimmunodeficient mice (Clinical and Experimental Immunology, 157: 104-118(2009)). 17 six-week-old male NSG mice purchased from Charles RiverLaboratories Japan, Inc. were irradiated with X-rays of 2.0 Gy (HitachiX-ray irradiation apparatus MBR-1520R-4). Then, the mice were dividedinto 1 group involving two mice and 3 groups each involving 5 mice.hR198_HG1/LG1 prepared at 3 mg/mL and 6 mg/mL with HBSor (25 mMhistidine/5% sorbitol, pH 6.0) was intravenously administered at 10mL/kg, i.e., 30 mg/kg and 60 mg/kg, to the tails of the mice of 2 groups(n=5). Only HBSor was administered to a further 1 group (n=5) as avehicle group. On the next day, frozen human PBMC (Cellular TechnologyLtd.) was thawed using CTL-antiaggregate (Cellular Technology Ltd.)according to the protocol, and 3,000,000 cells of human PBMC weresuspended in 200 μL of PBS and transplanted into the mice of the 3groups (n=5), while the human PBMC was not transplanted to the 1 group(n=2), which was observed over time as an X-ray irradiated controlgroup. 0, 7, 14, and 21 days after the X-ray irradiation, hR198_HG1/LG1or HBSor was administered at the same dose as above to theadministration groups. The body weight of each mouse was measured atdays 0, 1, 4, 7, 9, 10, 11, and 13, and subsequently every day. Changein body weight was calculated in percentage terms with the body weightat day 0 defined as 100%. The change in the average body weight of eachgroup is shown in FIG. 55. Decrease in the average body weight of thevehicle administration group started to be observed from about day 16.The experiment was terminated at day 21 when the average body weight ofthe vehicle administration group fell below 80%. At this point in time,the X-ray irradiated control group that had not received human PBMC didnot exhibit weight loss. The mice given hR198_HG1/LG1 at 30 mg/kg and 60mg/kg did not lose their body weights, and the average body weight wasequivalent to that of the human PBMC non-transplanted mice.hR198_HG1/LG1 (anti-Orai1 antibody) which remarkably suppressed thesymptoms of graft versus host disease caused by the activation of humanPBMC in this system is expected to have a therapeutic and/orprophylactic effect on human graft versus host disease.

16)-2 In Vivo Activity Evaluation of hR198_HG1/LG1 Using Human Orai1Knock-in Mouse

16)-2-1 Preparation of Human Orai1 Knock-in Mouse

Human Orai1 knock-in mice in which the amino acid sequence of theextracellular loop domain of mouse Orai1 was replaced with a human Orai1sequence were prepared by Institute of Immunology Co., Ltd. according toa standard method of genetically engineered mouse preparation. In short,a human Orai1 gene knock-in targeting vector was constructed byreplacing the DNA sequence of a BAC clone coding region comprising themouse Orai1 gene locus with the human Orai1 gene locus while introducingthereto a neomycin resistance gene flanked by loxP sequences. Mouse EScells were transfected with this targeting vector to establish a G418resistant line. An ES cell line having the specifically recombinedtarget gene locus was screened by Southern hybridization. The selectionmarker was removed by transfection with a Cre expression vector, and theresulting ES cell line was utilized to prepare chimeric F1 mice.Genotyping was carried out by Southern hybridization to selectheterozygous mutant individuals from among the F1 mice. The selected F1heterozygous mutant individuals were mated to prepare human Orai1knock-in mice as F2 homozygous mutants.

16)-2-2 Passive Cutaneous Anaphylaxis (PCA) Reaction Suppressing Effectof hR198_HG1/LG1

Mouse PCA reaction was carried out according to a standard method.Eight-week-old human Orai1 knock-in mice produced by Institute ofImmunology Co., Ltd., or wild type litter mice were retained inpositioners. Then, hR198_HG1/LG1 prepared at 6 mg/mL with HBSor wasintravenously administered at 10 mL/kg, i.e., 60 mg/kg, to the tails ofthe mice. Only HBSor was administered to a vehicle group. On the nextday, 10 μL of Monoclonal anti-OVA IgE (Chondrex, Inc.) adjusted to 10μg/mL with physiological saline was intracutaneously administered to theauricle of each mouse under inhalation anesthesia with isoflurane(Pfizer Japan Inc.). After 24 hours, physiological saline containing 2mg/mL OVA (Albumin from chicken egg white, Sigma-Aldrich Corp.) and 20mg/mL Evans blue (Merck KGaA) was intravenously administered at 5 mg/kgOVA and 100 mg/kg Evans blue to the tail. After 30 minutes, each mousewas sacrificed by bloodletting under deep anesthesia with isoflurane,and its auricle was excised and dipped in 0.5 mL of DMSO, followed bythe extraction of Evans blue (37° C., 72 hours). The DMSO solutioncontaining the extracted Evans blue was transferred at 200 μL/well to a96-well microplate, and O.D. 650 nm was measured using a microplatereader (Molecular Devices Corp., SpectraMax M5e). The absorbance of theextravasated Evans blue was determined according to a calculation methodgiven below and indicated with the average value of the vehicleadministration group defined as 100%. The absorbance of a DMSO solutionwas determined as a blank. %=(OD650 sample−OD650 blank)/(OD650vehicle−OD650 blank). FIG. 56 shows that hR198_HG1/LG1 suppresses thePCA reaction induced in human Orai1 knock-in mice. The mouse PCAreaction is a basic model system of immediate type allergy reproducinganaphylaxis, which is type I allergic reaction in humans, and thissystem is known to be usable in the evaluation of antiallergic drugs(Archives internationales de pharmacodynamie et de therapie, 165: 92-102(1967); and International archives of allergy and applied immunology,78: 113-117 (1985)). hR198_HG1/LG1 (anti-Orai1 antibody), confirmed inthis system to have inhibitory activity against IgE dependent mast celldegranulation, is expected to have a therapeutic and/or prophylacticeffect on bronchial asthma, allergic rhinitis, and atopic dermatitisfound in existing mast cell degranulation inhibitors, and similar type Iallergic diseases in humans, for example, allergic asthma.

16)-2-3 Delayed Type Hypersensitivity (DTH) Reaction Suppressing Effectof hR198_HG1/LG1

Mouse DTH reaction was carried out according to a standard method.Eight-week-old human Orai1 knock-in mice produced by Institute ofImmunology Co., Ltd., or wild type litter mice were retained inpositioners. Then, hR198_HG1/LG1 prepared at 6 mg/mL with HBSor wasintravenously administered at 10 mL/kg, i.e., 60 mg/kg, to the tails ofthe mice. Only HBSor was administered to a vehicle group. On the nextday, 50 μL of an emulsion prepared by mixing mBSA (Albumin BovineMethylated, Sigma-Aldrich Corp.) diluted into 5 mg/mL with physiologicalsaline and a Freund's complete adjuvant (Difco Laboratories) in equalamounts was subcutaneously administered to each of both axillae of eachmouse for immunization. After 6 days, hR198_HG1/LG1 was intravenouslyadministered again at 60 mg/kg to the tail. On the next day, mBSAprepared at 0.5 mg/mL with physiological saline, and physiologicalsaline were each intracutaneously administered to the lower leg underinhalation anesthesia with isoflurane. 6, 24, and 48 hours after theadministration, swelling in the leg was measured using a dial gauge.Time dependent change in the thickness of the swelling in the leg wascalculated with the swelling at 0 hours as 0 (10⁻² mm) and determinedwith the average value of the vehicle administration group defined as100%. FIGS. 57A-57C shows that hR198_HG1/LG1 suppressed the DTH reactioninduced in the human Orai1 knock-in mice at each point in time of 6hours (A), 24 hours (B), and 48 hours (C) after the antigenadministration. The mouse DTH reaction is a system for observing theestablishment and response of T cell dependent immunization, and it iswell known that a drug exhibiting activity in this system was developedas a strong immunosuppressant (Clinical and Experimental Immunology, 52:599-606 (1983)). hR198_HG1/LG1 (anti-Orai1 antibody), confirmed in thissystem to have suppressing activity against T cell immunization, isexpected to have a therapeutic and/or prophylactic effect on responsesof the body or diseases caused by T cells activity in humans, forexample, transplant rejections, immunological diseases, and inflammatorydiseases.

16)-2-4 Study on Suppressing Activity of Anti-Orai1 Antibody AgainstDermatitis

Dermatitis is induced by any of the following methods: 0.5 mL of analbumin antigen solution is intraperitoneally administered to a mouse,and after 2 weeks, the same amount as above of the antigen is injectedthereto as a booster. Then, the albumin antigen solution is repetitivelyapplied to the ear (20 μL) or the back (100 μL) 3 to 6 times at 3 day to2 week intervals. Alternatively, a mite antigen cream is repetitivelyapplied to the ear (20 μL) or the back (100 μL) 3 to 6 times at 3 day to2 week intervals. A hapten picryl chloride or dinitrofluorobenzene isprepared according to the protocol and applied to the ear (20 μL) or theback (100 μL) once or twice a week for 8 weeks at the maximum.Alternatively, a cutaneous reaction-inducing substance histamine,Compound 40/80, 5- (and 6-) carboxyfluorescein diacetate succinimidylester, fluorescein isothiocyanate, or bombesin-like peptide isadministered to the ear (20 μL), the back (100 μL), or the spinal cord(5 μL). The anti-Orai1 antibody is intravenously or subcutaneouslyadministered one day before the dermatitis induction or 1 hour to 4hours before the dermatitis induction. Then, the frequency ofadministration is set to 7 day to 28 day intervals to continue theantibody administration. After the dermatitis induction, the measurementof the auricle thickness using a dial thickness gauge or the macroscopicscoring of dermatitis is carried out over time. After the completion ofthe test period, the quantification of the concentrations of theantibody, cytokines, or serum biomarkers in blood or tissues, theexamination of the growth activity, cytokine producing ability, surfaceantigens, or the like of cells obtained from the skin, peripheral blood,the thymus, the spleen, the lymph node, or the bone marrow,histopathological analysis, etc. are carried out to determine thesuppressing activity of the anti-Orai1 antibody against dermatitis.

16)-2-5 Study on Suppressing Activity of Anti-Orai1 Antibody AgainstPsoriasis

In the case of using imiquimod, psoriatic dermatitis is induced byapplication to both sides or one side of the auricle (5 to 30 mg) andthe shaved back (50 to 100 mg). Alternatively, dermatitis is induced bythe intraperitoneal administration of 200 μL of a 10 mg/mL zymosansuspension in a phosphate buffer solution. In the case of using acytokine (IL-23, etc.) as a prophlogistic substance, psoriaticdermatitis is induced by the intracutaneous administration of 20 to 50μL of a solution containing 0.1 to 2 μg of the cytokine to one side ofthe mouse auricle under deep anesthesia with 1 to 5% isoflurane. Theanti-Orai1 antibody is intravenously or subcutaneously administered oneday before the dermatitis induction or 1 hour to 4 hours before thedermatitis induction. Then, the frequency of administration is set to 7day to 28 day intervals to continue the antibody administration. Afterthe dermatitis induction, the measurement of the auricle thickness usinga dial thickness gauge or the macroscopic scoring of dermatitis iscarried out over time. After the completion of the test period, theexamination of the weight of an inflammation site, the myeloperoxidaseactivity of neutrophils infiltrated into the site, the flow cytometryanalysis of the infiltrated cells, gene analysis, cytokine concentrationmeasurement, etc. are carried out to determine the suppressing activityof the anti-Orai1 antibody against psoriasis.

16)-2-6 Study on Suppressing Activity of Anti-Orai1 Antibody AgainstMultiple Sclerosis

Myelin oligodendrocyte glycoprotein or a peptide antigen thereof isadjusted to 4 mg/mL with physiological saline and emulsified by mixingwith a Freund's complete adjuvant adjusted to 8 mg/mL with physiologicalsaline, in equal amounts. 200 μL of this mixed solution isintracutaneously administered to the flank or abdominal region of amouse. Immediately thereafter, 100 μL of a 2 μg/mL aqueous pertussistoxin solution is administered to this mouse from the tail vein. After 2days, the pertussis toxin solution mentioned above is furtheradministered again from the tail vein to induce experimentalencephalomyelitis. After 1 week to 2 weeks into the experiment,encephalomyelitis develops, and paralysis expands from the tail to thelower legs and the anterior limbs. The degree of this paralysis isscored by macroscopically observing the movement of the limbs and thetail. The anti-Orai1 antibody is intravenously or subcutaneouslyadministered one day before the encephalomyelitis induction or 1 hour to4 hours before the encephalomyelitis induction. Then, the frequency ofadministration is set to 7 day to 28 day intervals to continue theantibody administration. The effect of the administration of theanti-Orai1 antibody on multiple sclerosis is determined.

16)-2-7 Study on Suppressing Activity of Anti-Orai1 Antibody AgainstArthritis

100 μL of an emulsion obtained by mixing 2 mg/mL bovine type II collagenand a Freund's complete adjuvant at a volume ratio of 1:1.3 isintracutaneously administered to the tail base of a mouse using a 1 mLsyringe and a tuberculin needle. After 2 to 3 weeks, the same treatmentas above is carried out. Then, joint swelling in the limbs is scoredmacroscopically or using a dial thickness gauge. At the completion ofthe test period, the concentrations of the antibody, cytokines, or serumbiomarkers in blood or tissues, the growth activity, cytokine producingability, or surface antigens of cells obtained from the skin, peripheralblood, the thymus, the spleen, the lymph node, or the bone marrow, etc.are measured. The anti-Orai1 antibody is intravenously or subcutaneouslyadministered one day before the arthritis induction or 1 hour to 4 hoursbefore the arthritis induction. Then, the frequency of administration isset to 7 day to 28 day intervals to continue the antibodyadministration. The effect of the administration of the anti-Orai1antibody on arthritis is determined.

16)-2-8 Study on Suppressing Activity of Anti-Orai1 Antibody AgainstColitis

Lymphocytes collected and purified from the lymph node and the spleen ofa human Orai1 knock-in mouse are isolated with a cell sorter using ananti-CD4 antibody GK1.5, an anti-CD25 antibody PC61.5, and an anti-CD45Rantibody C363.16A (all from eBioscience). The cells obtained by thismethod are confirmed in a flow cytometer to be CD4+CD25-CD45RBhi T-cellshaving a purity of 95% or higher. Then, 500,000 cells areintraperitoneally transplanted to a 12- to 16-week-old Rag2−/− mouse.Then, body weight measurement and observation of symptoms such asdiarrhea are carried out for 12 weeks. After the completion of theobservation period, the degree of thickening of the intestinal tract,the number and size of polyps, and the presence or absence ofpathological signs are examined by autopsy. Also, the concentrations ofthe antibody, cytokines, or serum biomarkers in blood or tissues arequantified, and the growth activity, cytokine producing ability, surfaceantigens, or the like of cells obtained from the intestinal tract,peripheral blood, the thymus, the spleen, the lymph node, or the bonemarrow are analyzed. The anti-Orai1 antibody is intravenously orsubcutaneously administered one day before the cell transplantation or 1hour to 4 hours before the cell transplantation. Then, the frequency ofadministration is set to 7 day to 28 day intervals to continue theantibody administration. The effect of the administration of theanti-Orai1 antibody on colitis is determined.

16)-2-9 Study on Effect of Anti-Orai1 Antibody on Bone Marrow CellTransplantation System

Thigh bone and shinbone are excised from a human Orai1 knock-in mouse,and the cells in the bone marrow are pushed out by the injection of 1 to5 mL of an RPMI1640 medium containing 10% FBS from the epiphysis using asyringe with a needle. After treatment with a cell strainer, the bonemarrow cells are recovered by centrifugation and adjusted such that10,000,000 bone marrow cells are contained in 200 μL of an injectionbuffer containing 10 mM HEPES, 0.5 mM EDTA, and 0.5%penicillin/streptomycin. At the same time therewith, spleen cells arecollected from the spleen of the human Orai1 knock-in mouse according toa standard method. A 10- to 13-week-old BALB/c mouse as a recipient isirradiated with X-rays of 2.0 to 8.0 Gy. Then, 0 to 4,000,000 donorspleen cells are added to 200 μL of the donor bone marrow cells, andthis cell mixed solution is injected to the tail vein of the recipient.Then, change in body weight and survival rate are examined for 4 to 16weeks. At the completion of the test, the concentrations of theantibody, cytokines, or serum biomarkers in the blood or the tissues ofthe recipient mouse, and the surface antigens, growth activity, orcytokine producing ability of cells obtained from the intestinal tract,peripheral blood, the thymus, the spleen, the lymph node, or the bonemarrow are measured. The anti-Orai1 antibody is intravenously orsubcutaneously administered to the recipient mouse one day before thebone marrow transplantation or 1 hour to 4 hours before the bone marrowtransplantation. Then, the frequency of administration is set to 7 dayto 28 day intervals to continue the antibody administration. The effectof the anti-Orai1 antibody on the engraftment of the transplanted cellsor the incidence of graft versus host disease is determined.

[Example 17] Comparison of Physicochemical Properties Between AffinityMatured Antibody and Other Anti-Human Orai1 Antibodies

Viscosity Measurement Using m-VROC

hR198_HG1/LG1 or hR198_H3/LG1 prepared in 10)-3, hR198_HG1-LALA/LG1prepared in 12)-3, or 2C1.1 prepared in 13)-6 was concentrated to 150mg/mL or higher with VIVAPORE 5 (Sartorius Japan K.K.) and then preparedat 90, 120, and 150 mg/mL with HBSor. The viscosity at 25° C. wasmeasured three times for each concentration using m-VROC (RheoSense,Inc.) to calculate an average viscosity (mPa·s). The results are shownin FIG. 58 and Table 1. The viscosities of hR198_HG1/LG1, hR198_H3/LG1,and hR198_HG1-LALA/LG1 at all of the concentrations were lower than theviscosity of 2C1.1. Particularly, at 150 mg/mL, the viscosities ofhR198_HG1/LG1, hR198_H3/LG1, and hR198_HG1-LALA/LG1 were 11.4, 10.0, and10.8 mPa·s, respectively, whereas the viscosity of 2C1.1 was 21.0 mPa·s,demonstrating that the affinity matured antibodies have a low viscosityeven at a high concentration, as compared with 2C1.1.

TABLE 1 Average SD Concentration Viscosity Viscosity Sample [mg/mL] [mPa· s] [mPa · s] hR198_HG1/LG1 90 3.74 0.05 120 6.11 0.02 150 11.43 0.09hR198_H3/LG1 90 3.66 0.04 120 5.78 0.07 150 9.98 0.10 hR198_HG1-LALA/LG190 3.74 0.06 120 5.68 0.20 150 10.82 0.37 2C1.1 90 4.05 0.02 120 8.670.12 150 20.96 0.08

INDUSTRIAL APPLICABILITY

The humanized anti-Orai1 antibody of the present invention has astronger T cell activity inhibitory effect than that of antibodies knownin the art, and can serve as a therapeutic or prophylactic agent fortransplantation rejection, etc.

FREE TEXT OF SEQUENCE LISTING

SEQ ID NO: 1: Gene sequence of human Orai1

SEQ ID NO: 2: Amino acid sequence of human Orai1

SEQ ID NO: 3: PCR primer Nhe-polyC-S

SEQ ID NO: 4: PCR primer rIgγ-AS1

SEQ ID NO: 5: PCR primer rIgγ-AS2

SEQ ID NO: 6: PCR primer Nhe-polyC-S

SEQ ID NO: 7: PCR primer rIgκ-AS

SEQ ID NO: 8: Sequencing primer rIgγ-seq

SEQ ID NO: 9: Sequencing primer rIgκ-seq

SEQ ID NO: 10: Nucleotide sequence encoding the R118 light chain

SEQ ID NO: 11: Amino acid sequence of the R118 light chain

SEQ ID NO: 12: Nucleotide sequence encoding the R118 heavy chain

SEQ ID NO: 13: Amino acid sequence of the R118 heavy chain

SEQ ID NO: 14: Nucleotide sequence encoding the R198 light chain

SEQ ID NO: 15: Amino acid sequence of the R198 light chain

SEQ ID NO: 16: Nucleotide sequence encoding the R198 heavy chain

SEQ ID NO: 17: Amino acid sequence of the R198 heavy chain

SEQ ID NO: 18: DNA fragment comprising a sequence encoding a human κchain secretion signal and a human κ chain constant region

SEQ ID NO: 19: PCR primer 3.3-F1

SEQ ID NO: 20: PCR primer 3.3-R1

SEQ ID NO: 21: DNA fragment comprising a sequence encoding a human heavychain signal sequence and amino acids of a human IgG1 constant region

SEQ ID NO: 22: Nucleotide sequence encoding the human chimerized cR118light chain

SEQ ID NO: 23: Amino acid sequence of the human chimerized cR118 lightchain

SEQ ID NO: 24: Nucleotide sequence encoding the human chimerized cR198light chain

SEQ ID NO: 25: Amino acid sequence of the human chimerized cR198 lightchain

SEQ ID NO: 26: Nucleotide sequence encoding the human chimerized cR118heavy chain

SEQ ID NO: 27: Amino acid sequence of the human chimerized cR118 heavychain

SEQ ID NO: 28: Nucleotide sequence encoding the human chimerized cR198heavy chain

SEQ ID NO: 29: Amino acid sequence of the human chimerized cR198 heavychain

SEQ ID NO: 30: Nucleotide sequence encoding the hR198_L1 type lightchain

SEQ ID NO: 31: Amino acid sequence of the hR198_L1 type light chain

SEQ ID NO: 32: Nucleotide sequence encoding the hR198_L2 type lightchain

SEQ ID NO: 33: Amino acid sequence of the hR198_L2 type light chain

SEQ ID NO: 34: Nucleotide sequence encoding the hR198_L3 type lightchain

SEQ ID NO: 35: Amino acid sequence of the hR198_L3 type light chain

SEQ ID NO: 36: Nucleotide sequence encoding the hR198_L4 type lightchain

SEQ ID NO: 37: Amino acid sequence of the hR198_L4 type light chain

SEQ ID NO: 38: Nucleotide sequence encoding the hR198_H1 type heavychain

SEQ ID NO: 39: Amino acid sequence of the hR198_H1 type heavy chain

SEQ ID NO: 40: Nucleotide sequence encoding the hR198_H2 type heavychain

SEQ ID NO: 41: Amino acid sequence of the hR198_H2 type heavy chain

SEQ ID NO: 42: Nucleotide sequence encoding the hR198_H3 type heavychain

SEQ ID NO: 43: Amino acid sequence of the hR198_H3 type heavy chain

SEQ ID NO: 44: Nucleotide sequence encoding the hR198_H4 type heavychain

SEQ ID NO: 45: Amino acid sequence of the hR198_H4 type heavy chain

SEQ ID NO: 46: PCR primer Orai1 HF

SEQ ID NO: 47: PCR primer Orai1 CH FR

SEQ ID NO: 48: PCR primer M13 rev long

SEQ ID NO: 49: PCR primer SecM Stop R

SEQ ID NO: 50: PCR primer Orai1 Lc F

SEQ ID NO: 51: PCR primer Orai1 CL-FR

SEQ ID NO: 52: PCR primer Orai1 HR-FLAG R

SEQ ID NO: 53: PCR primer Orai1 CL-FLAG R

SEQ ID NO: 54: PCR primer Myc-R

SEQ ID NO: 55: Nucleotide sequence encoding the hR198_LG1 type lightchain

SEQ ID NO: 56: Amino acid sequence of the hR198_LG1 type light chain

SEQ ID NO: 57: Nucleotide sequence encoding the hR198_LG2 type lightchain

SEQ ID NO: 58: Amino acid sequence of the hR198_LG2 type light chain

SEQ ID NO: 59: Nucleotide sequence encoding the hR198_LG3 type lightchain

SEQ ID NO: 60: Amino acid sequence of the hR198_LG3 type light chain

SEQ ID NO: 61: Nucleotide sequence encoding the hR198_HG1 type heavychain

SEQ ID NO: 62: Amino acid sequence of the hR198_HG1 type heavy chain

SEQ ID NO: 63: Nucleotide sequence encoding the hR198_HG2 type heavychain

SEQ ID NO: 64: Amino acid sequence of the hR198_HG2 type heavy chain

SEQ ID NO: 65: Nucleotide sequence encoding the hR198_HG3 type heavychain

SEQ ID NO: 66: Amino acid sequence of the hR198_HG3 type heavy chain

SEQ ID NO: 67: Nucleotide sequence encoding the hR198_H4-LALA type heavychain

SEQ ID NO: 68: Amino acid sequence of the hR198_H4-LALA type heavy chain

SEQ ID NO: 69: Nucleotide sequence encoding the hR198_HG1-LALA typeheavy chain

SEQ ID NO: 70: Amino acid sequence of the hR198_HG1-LALA type heavychain

SEQ ID NO: 71: DNA fragment comprising a sequence encoding a human heavychain secretion signal and amino acids of a human IgG2 constant region

SEQ ID NO: 72: Nucleotide sequence encoding the 2C1.1 antibody heavychain

SEQ ID NO: 73: Amino acid sequence of the 2C1.1 antibody heavy chain

SEQ ID NO: 74: Nucleotide sequence encoding the 2C1.1 antibody lightchain

SEQ ID NO: 75: Amino acid sequence of the 2C1.1 antibody light chain

SEQ ID NO: 76: Nucleotide sequence encoding the 5H3.1 antibody heavychain

SEQ ID NO: 77: Amino acid sequence of the 5H3.1 antibody heavy chain

SEQ ID NO: 78: Nucleotide sequence encoding the 5H3.1 antibody lightchain

SEQ ID NO: 79: Amino acid sequence of the 5H3.1 antibody light chain

SEQ ID NO: 80: Nucleotide sequence encoding the 10F8 antibody heavychain

SEQ ID NO: 81: Amino acid sequence of the 10F8 antibody heavy chain

SEQ ID NO: 82: Nucleotide sequence encoding the 10F8 antibody lightchain

SEQ ID NO: 83: Amino acid sequence of the 10F8 antibody light chain

SEQ ID NO: 84: Nucleotide sequence encoding the 14F74 antibody heavychain

SEQ ID NO: 85: Amino acid sequence of the 14F74 antibody heavy chain

SEQ ID NO: 86: Nucleotide sequence encoding the 14F74 antibody lightchain

SEQ ID NO: 87: Amino acid sequence of the 14F74 antibody light chain

SEQ ID NO: 88: Nucleotide sequence encoding the 17F6 antibody heavychain

SEQ ID NO: 89: Amino acid sequence of the 17F6 antibody heavy chain

SEQ ID NO: 90: Nucleotide sequence encoding the 17F6 antibody lightchain

SEQ ID NO: 91: Amino acid sequence of the 17F6 antibody light chain

SEQ ID NO: 92: Rat CDRL1 (which was derived from R198 and used for thehR198_L1 to hR198_L4 type light chains)

SEQ ID NO: 93: Engineered CDRL1 (which was used for the hR198_LG1 typelight chain)

SEQ ID NO: 94: Engineered CDRL1 (which was used for the hR198_LG2 typelight chain)

SEQ ID NO: 95: Engineered CDRL1 (which was used for the hR198_LG3 typelight chain)

SEQ ID NO: 96: Rat CDRL2 (which was common to R118 and R198 and used forthe hR198_L1 to hR198_L4 and hR198_LG1 type light chains)

SEQ ID NO: 97: Engineered CDRL2 (which was used for the hR198_LG2 typelight chain)

SEQ ID NO: 98: Engineered CDRL2 (which was used for the hR198_LG3 typelight chain)

SEQ ID NO: 99: Rat CDRL3 (which was derived from R118 and used for thehR198_L3 and hR198_L4 type light chains)

SEQ ID NO: 100: Rat CDRL3 (which was derived from R198 and used for thehR198_L1 and hR198_L2 type light chains)

SEQ ID NO: 101: Engineered CDRL3 (which was used for the hR198_LG1 tohR198_LG3 type light chains)

SEQ ID NO: 102: Rat CDRH1 (which was derived from R118 and used for thehR198_H3, hR198_H4, and hR198_HG1 to hR198_HG3 type heavy chains)

SEQ ID NO: 103: Rat CDRH1 (which was derived from R198 and used for thehR198_H1 and hR198_H2 type heavy chains)

SEQ ID NO: 104: Rat CDRH2 (which was derived from R118 and used for thehR198_H3 and hR198_H4 type heavy chains)

SEQ ID NO: 105: Rat CDRH2 (which was derived from R198 and used for thehR198_H1 and hR198_H2 type heavy chains)

SEQ ID NO: 106: Engineered CDRH2 (which was used for the hR198_HG1 typeheavy chain)

SEQ ID NO: 107: Engineered CDRH2 (which was used for the hR198_HG2 typeheavy chain)

SEQ ID NO: 108: Engineered CDRH2 (which was used for the hR198_HG3 typeheavy chain)

SEQ ID NO: 109: Rat CDRH3 (which was common to R118 and R198 and usedfor the hR198_H1 to hR198_H4 type heavy chain

SEQ ID NO: 110: Engineered CDRH3 (which was used for the hR198_HG1 tohR198_HG3 type heavy chains)

SEQ ID NO: 111: Nucleotide sequence encoding the hR198_H0 type heavychain

SEQ ID NO: 112: Amino acid sequence of the hR198_H0 type heavy chain

SEQ ID NO: 113: Nucleotide sequence encoding the hR198_H5 type heavychain

SEQ ID NO: 114: Amino acid sequence of the hR198_H5 type heavy chain

SEQ ID NO: 115: Biotin-PEGylated human Orai1 loop region peptidesequence

SEQ ID NO: 116: Rat CDRL1 (which was derived from R118, but was not usedfor humanized antibodies)

The invention claimed is:
 1. An antibody or an antigen binding fragmentof the antibody which specifically binds to the amino acid sequencerepresented by SEQ ID NO: 2, wherein the heavy chain sequence comprisesa variable region having CDRH1, CDRH2, and CDRH3, wherein the CDRH1consists of the amino acid sequence represented by SEQ ID NO: 102, theCDRH2 consists of an amino acid sequence represented by any one of SEQID NOs: 104, 106, 107, and 108, and the CDRH3 consists of an amino acidsequence represented by SEQ ID NO: 109 or 110; and the light chainsequence comprises a variable region having CDRL1, CDRL2, and CDRL3,wherein the CDRL1 consists of an amino acid sequence represented by anyone of SEQ ID NOs: 93, 94, and 95, the CDRL2 consists of an amino acidsequence represented by any one of SEQ ID NOs: 96, 97, and 98, and theCDRL3 consists of the amino acid sequence represented by SEQ ID NO: 101.2. The antibody or the antigen binding fragment of the antibodyaccording to claim 1, wherein the heavy chain sequence comprises avariable region having CDRH1, CDRH2, and CDRH3, wherein the CDRH1consists of the amino acid sequence represented by SEQ ID NO: 102, theCDRH2 consists of the amino acid sequence represented by SEQ ID NO: 106,and the CDRH3 consists of the amino acid sequence represented by SEQ IDNO: 110; and the light chain sequence comprises a variable region havingCDRL1, CDRL2, and CDRL3, wherein the CDRL1 consists of the amino acidsequence represented by SEQ ID NO: 93, the CDRL2 consists of the aminoacid sequence represented by SEQ ID NO: 96, and the CDRL3 consists ofthe amino acid sequence represented by SEQ ID NO:
 101. 3. The antibodyor the antigen binding fragment of the antibody according to claim 1,wherein the antibody comprises a heavy chain variable region sequenceconsisting of amino acid residues from positions 20 to 136 in the aminoacid sequence represented by SEQ ID NO: 62 and a light chain variableregion sequence consisting of amino acid residues from positions 21 to126 in the amino acid sequence represented by SEQ ID NO:
 56. 4. Theantibody or the antigen binding fragment of the antibody according toclaim 3, wherein the antibody consists of a heavy chain sequenceconsisting of amino acid residues from positions 20 to 465 or 20 to 466in the amino acid sequence represented by SEQ ID NO: 62 and a lightchain sequence consisting of amino acid residues from positions 21 to234 in the amino acid sequence represented by SEQ ID NO:
 56. 5. Theantibody or the antigen binding fragment of the antibody according toclaim 3, wherein the antibody consists of a heavy chain sequenceconsisting of amino acid residues from positions 20 to 465 or 20 to 466in the amino acid sequence represented by SEQ ID NO: 70 and a lightchain sequence consisting of amino acid residues from positions 21 to234 in the amino acid sequence represented by SEQ ID NO:
 56. 6. Theantigen binding fragment of the antibody according to claim 1, whereinthe antigen binding fragment is selected from the group consisting ofFab, F(ab′) 2, Fab′, and Fv.
 7. The antibody according to claim 1,wherein the antibody is an scFv.
 8. A pharmaceutical compositioncomprising at least any one antibody or antigen binding fragment of theantibody according to claim 1.